DinoBlag: Shonisaurus

(A picture of the animal in question by Dmitry Bogdanov. It doesn't belong to me!)
Finally! A marine reptile gets some time in the spotlight. Shonisaurus is the largest of any marine reptile yet discovered. There are two species within the genus: S. popularis and S. sikanniensis, the latter being the larger of the two at an estimated 69 feet (21 meters) in length. Shonisaurus belongs to the family Shastasauridae within the order Ichthyosauria, and its closest relatives include Besanosaurus and Shastasaurus.

Shonisaurus lived during the Norian stage of the Upper Triassic, and has been found in Nevada, British Columbia, and possibly the Himalayas. It posesses several traits, such as relatively long and thin flippers, which seem to suggest that it does not belong to the main branch of the ichthyosaurian evolutionary tree, and instead belongs to a sort of offshoot from that group.

It posessed several conical teeth which existed only at the front of its mouth, and a rather large body for an ichthyosaur.

Princeton Field Guide to Dinosaurs, etc.

But never mind all that golden eagle business. Look what I got!

It's so beautiful.

The Princeton Field Guide to Dinosaurs is Gregory S. Paul's latest book, and has detailed information on nearly every recognized (and some unrecognized) species of dinosaur, from the tiniest ornithopod to the tyrant kings. Accompanying the book's descriptions are Paul's splendid - as usual - artwork. The book is the most up-to-date dinosaur encyclopedia on the market now, to the best of my knowledge.

The book details the geographic and chronological distribution of the various dinosaurs, the formation they were found in, their habitat, their eating habits, what separates them from their relatives, and other notes. The book is enlightening and scholarly, while simultaneously having the benefit of being accessible to those who are less dino-literate.

I give this book the official SR Seal of Approval, and would recommend it to any lover of dinosaur paleontology in a heartbeat.

In unrelated news, the whole leopard gecko thing kinda fell through. I hope to get one eventually, but for the foreseeable future, I won't be getting one. Need to get the time and money together to buy one.

Meanwhile, in dinosaur-land, a battle is being waged over the fate of Raptorex (shudder), with some alleging that it is yet another juvenile Tarbosaurus (see: Alioramus), and others defending it, on the grounds that a certain ridge on its pelvis distinguishes it from that Asian tyrannosaur.

Personally, I hope Raptorex's name vanishes into the taxonomical trashbin, never to be seen again.

News of supposed Middle Jurassic bird footprints in Africa... Given Africa's scant Mesozoic record, I wouldn't be terribly surprised if this, and other unusual things in the future, may turn out to be true about this paleontological blank spot.

Hopefully, I'll give more updates in the near future and learn to stop slacking off. Wish me luck.

Coming Soon...

Golden eagles kill goats. For reals.

Oops

Ehehehe... Hey, look! It's Dryptosaurus!

-Insert poor excuse here-

Well, exams reared their ugly head, and I wasn't able to update much. Thankfully, it is now summer! And as such I have free time to kill!

Well, long story short, they described something like six new genera of ceratopsians while I was away, including the first of the horned dinosaurs from Europe, as well as the first true ceratopsid from outside North America, and the biggest horns in any dinosaur. The good stuff always happens while I'm away!

Dino Family Spotlight: Coelophysidae

Though most famous for its Triassic record, the coelophysids were a greatly successful group, surviving into the Early Jurassic across North America and Africa. They were light-boned, fleet-footed predators, well-suited to a world of small prey which could run just as fast as it could. They are placed within the Theropoda, and are believed to be more primitive than the ceratosaurs and tetanurans.

Coelophysis bauri was first described by Edward Drinker Cope in 1889 from fossils found in the American Southwest, but it's unsure if these fossils even belong to the dinosaur at all. Later bones attributed to Coelophysis definitely belong to a theropod dinosaur, and as such, Coelophysis is still a valid dinosaurian genus.

Coelophysidae is also home to what is, possibly, the worst dinosaur name ever: Megapnosaurus. Once beloved by dinosaur fans as Syntarsus, the entomologists struck again: Syntarsus was taken by a beetle. In some miscarriage of justice, the entomologists who pointed this out now had the right to rename the animal. It is now Megapnosaurus - "big dead reptile". I'm not sure if this shows a twisted sense of humor on the entomologists' parts, or simply ignorance as to the true nature of dinosaurs.

This family posesses seven species across six genera.

Coelophysidae (Nopsca, 1923)

Coelophysis bauri (Cope, 1889)

Megapnosaurus rhodesiensis (Raath, 1969)

Megapnosaurus kayentakatae (Rowe, 1989)

Camposaurus arizonensis (Hunt et al., 1998)

Podokesaurus holyokensis (Talbot, 1911)

Procompsognathus triassicus (Fraas, 1913)

Segisaurus halli (Camp, 1936)

(Sorry for paragraph-fail. I blame the website!)

Dino Family Spotlight: Herrerasauridae

Herrerasaurids are among the most primitive dinosaurs, and, indeed, are primitive enough to have caused debate in the paleontological community for a couple decades. Though the general concensus is that they are a family of primitive theropods, some scientists hold them to be more basal, belonging to Saurischia incertae sedis.

The type species, Herrerasaurus ischigualastensis, was described by Osvaldo Reig in 1963 in the Ischigualasto Formation of Brazil. The specimen variously jumped around into several different placements, from prosauropods and non-dinosaurian archosaurs, to a primitive carnosaur. Since then, the classification has settled to the two options found in the previous paragraph, and the group is defined as the most inclusive clade containing Herrerasaurus ischigualastensis, but not Passer domesticus.

The family dates to the Late Triassic, from about 228 to 225 million years ago. They are most commonly found in South America (Brazil & Argentina), but specimens are also known from North America (Arizona & Texas). The possibility remains that there could be others found on other continents. The group contains at least three species across at least three genera.

Order Saurischia
Suborder Theropoda
Family Herrerasauridae (Benedetto, 1973)
Herrerasaurus ischigualastensis (Reig, 1963)
Staurikosaurus pricei (Colbert, 1970)
Chindesaurus bryansmalli (Long & Murry, 1995)

Introducing: Dinosaur Family Spotlight!

Normally, in the spirit of the first day of April, I'd come up with something witty. But I'm rather tired today (and looking forward to my spring break!), so instead I'm announcing an upcoming segment on the blog (don't worry, Lizard Watch will be here soon). The Dino Family Spotlight!

For the benefit of those who view my page, I will go through every major grouping of dinosaurs (the families, but in some cases, subfamilies as well), and offer a summary of that group's features, and a list of species which belong in the group. The segment will begin tomorrow with the most primitive of the dinosaur families, Herrerasauridae.

Stay cool!

New Tyrannosauroids and Why I Dislike Ibises (Ibes?)

(Look, there's one now! Curse the little blighter!)

I've been out for a while (Disney World! Whoo!), and as such have not been able to post much on my blog. Two interesting things have happened recently occurred in the world of tyrant paleozoology. The first is a pubis (a hip bone) from a tyrannosauroid found in the Early Cretaceous of Dinosaur Cove, Australia.

This is the very same place where Leaellynasaura and the famous "dwarf allosaur" (now known to be a neovenatorid) were found. The bone is not enough to be considered diagnostic, so I applaud those who described it for not slapping it with a new name. (And I do mean you, Santanaraptor.) This is interesting, as before this find, tyrant dinosaurs are known only from the Laurasian continents of North America, Asia, and Europe. Does this mean that other tyrants might soon be found in India? Madagascar and Africa? South America? Who knows, maybe even Antarctica!

Second is the first tyrant known from Russia, a small tyrannosauroid named Kileskus aristotocus, from the Middle Jurassic of Western Siberia. Russia is notably sparse in dinosaur fossils, though many have been found in the Amur River Valley and in not-too-distant Kazakhstan and Uzbekistan. The animal is known from some premaxillary bones and other cranial elements, and is assumed to be a more basal relative of the Proceratosauridae and others.

And, to the main point of this little post... The American white ibis. Eudocimus albus. While at Disney World's Animal Kingdom, I leaned in to say "Hello!" to one of these small birds, and it snapped at me! Only my expert ninja skills (screaming like a girl and falling over) prevented me from sustaining a bruised nose. I can conclude that the bird was probably startled by the loud noise, and indeed, I'll have to remember not to bother any avians in the future.

Clearly the birds still contain predatory instincts from their dinosaur ancestors, among which are the hunting habits of birds of prey and extinct terror birds. Anyone who doubts me can go to Disney and try being friendly to an ibis.

Linheraptor exquisitus - A New Dromaeosaur!

If you couldn't tell by my user name, dromaeosaurs are my favorite among the dinosaurs. The raptors may not have been as big (or as scaly!) as the Velociraptor of Jurassic Park fame, but they were fast and effective hunters which survived over fifty million years.

So I'm excited about the discovery of yet another new dromaeosaur from the Cretaceous of Inner Mongolia, China, Linheraptor exquisitus. It was described a few days ago by a team including fellow paleo-blogger, David Hone of Archosaur Musings. At two meters long (this is a bit larger than six feet, I believe), it ranks similarly in size to the related Velociraptor. It lived about 75 million years ago in the Maastrichtian. If I had to guess, it is part of the Velociraptorinae, since Tsaagan and Velociraptor seem to be its closest relatives.

The specimen shown at the top is very well preserved, though sadly the tail doesn't seem to be visible in the picture.

Yet Another New Species: Abydosaurus mcintoshi

So far, 2010 is turning out to be quite a good year for dinosaur discovery. Abydosaurus mcintoshi was described this week by Chure et al. from skull and neck material found in Dinosaur National Monument. It dates from the Albian stage of the Early Cretaceous, about 105 million years ago.

Abydosaurus is a brachiosaurid, making it part of a relatively successful family of sauropod dinosaurs. More famous relatives, such as Brachiosaurus and Giraffatitan, are known mostly from the Late Jurassic, though some, such as Sauroposeidon, are also known from the Early Cretaceous. The brachiosaurids are a part of a group of sauropods known as macronarians, for their large nasal cavities (as opposed to those of diplodocoids).

Abydosaurus is notable for its relatively thin, peg-like teeth, which are quite different from those of the earlier Brachiosaurus. There is a marked change from the broad-crowned sauropod teeth of the Jurassic, which seems to have appeared independently among different sauropod groups throughout the Cretaceous. By the Upper Cretaceous, no broad-crown-toothed sauropods are found anywhere in the world.

Plurals in Latin! This is important.

Just to clear a few things up with plurals in Latin (since in paleontology, the language is dealt with often).

If it ends with -us, generally its plural ends with -i. Example: cactus -> cacti. Some other plurals for words, however, end with -era. Example: genus -> genera.

If it ends with -a, its plural ends with -ae. Examples: alumna -> alumnae, aurora -> aurorae.

If it ends in -um, its plural ends with -a. Examples: medium -> media, datum -> data. (Yes, data is plural.)

If it ends with -ix, its plural ends with -ices. Example: appendix -> appendices.

If it ends with -is, its plural ends with -es. Example: parenthesis -> parentheses.

Oddball words like species maintain their singular form in the plural.

I hope this brief guide helped you. The more you know. Because knowledge is power!

Lizard Watch

(Pictured: Eublepharis macularius. Not mine, though.)

Good news, everyone! Within the next few weeks, I will be obtaining my very own squamate, an Eublepharis macularius. Or, in common terms, a leopard gecko.

The Squamata are an order of scaled reptiles, the most recent major group, having found their origins around the lower Jurassic. The order includes not only lizards but snakes, thereby comprising the vast majority of sauropsids (reptiles) alive today. Other orders, including Crocodilia (within the Archosauria; Archosauria also contains birds and dinosaurs), Sphenodontia (tuataras), and Testudines (turtles and tortoises) make up the remainder of reptiles alive today. Of course, Squamata also contained the now-extinct mosasaurs, making my future scaley compadre a not so distant cousin of the great Tylosaurus proriger.

Within suborder Scleroglossa, the infraorder Gekkota, and family Gekkonidae, the leopard gecko originates from the arid scrubs and deserts of southern Asia, throughout Pakistan and India. It is unique among geckos, as it has eyelids. It's a well-established pet in many countries, common as a reptilian pet throughout the United States.

Like other geckos, it posesses over 14,000 hair-like growths called setae (singular: seta) on its feet, which allow it to walk on vertical surfaces without liquid or surface tension. Each of the setae has a diameter of about 5 micrometers, and each is covered with anywhere from 100 to 1000 spatulae, which are 0.2 micrometers in width.

I'm really looking forward to having my very own squamate around the house. However, I can only hope the two local Felis silvestris catus aren't quite as anxious about its arrival.

DinoBlag: Batrachotomus

A more esoteric choice on my part: Batrachotomus kupferzellensis. It is a prestosuchid rauisuchian from the Middle Triassic (Ladnian) of southern Germany. It was found in a swampy region, so it's no accident that its name means "frog cutter".

It grew up to 20 feet (6 meters) long, making it one of the larger of the rauisuchians. Rauisuchians are, of course, a suborder of crurotarsan archosarus, mostly land-bound crocodiles which lived from the Permian until the Triassic. They were very widespread, and have been found on nearly every continent. Batrachotomus is distinguished from its cousins by a series of bony, leaf-shaped scutes on its back known as osteoderms. This term means "bony skin", which is precisely what they were.

With a tall, narrow skull and a relatively upright posture, it is easy to see why Batrachotomus and its ilk ruled the Triassic world. It was well-suited for hunting the prey it needed to, as it was faster than most of them.

It lived in the same habitat as several large amphibians like Mastodonsaurus, nothosaurs, and relatives of the marine Tanystropheus.

DinoBlag: Bistahieversor

(Pictured: The skull of the animal in question.)

I know, right? Two blog posts in a day. Scandal. But hey, if I have the day off, why not?

I kinda missed the media hype a week or so past when this litte guy was discovered in the Kirtland Formation (formerly the Ojo Alamo Formation, after which the contemporary Alamosaurus was named). But now I can put him in a typical DinoBlag: Bistahieversor sealeyi. (Here, I'll help you out: bis-TAH-ee-eh-ver-ser SEEL-ee.)

Our friend Bis (as I will henceforce refer to him/her/it as) was gathered in the 1990s under the dubious name Aublysodon, which was attributed a century ago to the teeth of an unidentified juvenile tyrannosaur. Earlier last decade, it was attributed instead to a new species of Daspletosaurus, but research shows that it was different enough from Das (I'm a lazy typer) to belong to its own genus. And so, this year, Bistahieversor was born.

Its name means "Bistahi destroyer", Bistahi being the location where it was found, and a Navajo word meaning "formation of pueblos". Its adult size is estimated at 30 feet (9 meters), and it lived around 75 million years ago in the lower Maastrichtian. Though its affinities within the Tyrannosauroidea are uncertain, it has a deep snout, not unlike true tyrannosaurids.

Some scientists postulate that it was isolated from the more advanced northern tyrannosaurs by the growing Rocky Mountains, which at the time were far higher than today. By its skull characteristics, in my opinion, I would suppose that the dinosaur fed on hadrosaurs, much like its northern relatives Daspletosaurus, Albertosaurus, and Tyrannosaurus rex.

Bistahieversor sealeyi (Bis will catch on, you just watch!) was described by Carr and Williamson in 2010.

A Look to the Past - The Dinosaur Encyclopedia by Dr. Michael Benton

Dinosaur science has come a long, long way since 1984. Evidence enough of this is a book by Dr. Michael Benton, published that year, which recently resurfaced in my home. Compared with the graceful dinosaurs in Dr. Thomas Holtz's 2004 book with a similar title, the clunky, tripod-like dinosaurs of the older publication are almost comic in appearence.

Not that I blame Dr. Benton, of course. The book is 26 years old. A lot of discoveries have been made, and the book is quite comprehensive for the time. But a look back from over a quarter of a century can be an entertaining experience. A short list of the things said in the book is enough to warrant at least a quiet snicker.

*Tyrannosaurus is the largest carnivore of all time, at 50 feet. (It grew to 43 feet.)
*"Warm-blooded Dinosaurs?" is shown with a skeptical question mark in the index.
*Crocodiles are cited as dinosaurs' closest living relatives. Birds are overlooked.
*Poor Diplodocus is cited as the "most stupid dinosaur", as it has the lowest brain-to-body ratio of any dinosaur. (I don't know if this is still true or not. I'll have to check.

Even the taxonomical differences between then and now are enough to fill this post.

*Tyrannosaurids are Carnosaurs (They're coeulurosaurs.)
*"Anatosaurus", rather than Anatotitan.
*At least it doesn't use "Brontosaurus" as a valid name!
*Oviraptorosaurs are ornithomimosaurs (They're not.)
*All large carnivores, including coelophysoid Dilophosaurus, megalosauroid Megalosaurus and Spinosaurus, and, as mentioned before, tyrannosauroid Tyrannosaurus are apparently Carnosauria.
* Smaller coelophysoids are coelurosaurs (They're not!)
*Therizinosaurus and Deinocheirus are in the Deinocheiridae, which is apparently part of Deinonychosauria. (That's a new one.)
*"Dravidosaurus"
*Elaphrosaurus is an ornithomimosaur (It's a ceratosaur)
*Interestingly, Hypselosaurus is cited as being closely related to Alamosaurus, Saltasaurus, and Titanosaurus, all of which (including Hypselosaurus) would, in 1993, be classed into Titanosauria. (More points for Dr. Benton!)
*It suggests that Mamenchisaurus stood in the middle of ponds and swept around like a vacuum cleaner to eat.
*Noasaurus is claimed to be a deinonychosaur, which would have made it the only of that kind known from South America. Ironically, it wasn't until decades later that unenlagiine dromaeosaurids were found in the same area.
*Pachycephalosaurus is said to be an ornithopod. (It's a cerapod.)
*Though rightfully told to be a saurischian, Segnosaurus is said to be a fish-eater, as this was originally how it was thought to feed. It was, in reality, either herbivorous or omnivorous like other therizinosaurs.
*Spinosaurus is shown as a close relative of Acrocanthosaurus.
*Syntarsus (now Megapnosaurus, or big dead lizard, which is just about the worst dinosaur name ever; no surprise, it wasn't named by actual paleontologists) was one of the first dinosaurs depicted with feathers, but the author approaches this claim with much caution.

But, of course, again, we can't blame Dr. Benton. This was another age (at least in dinosaur science). The book has some very informative parts in the back about the history of the science, as well as the preparation of mounted dinosaur skeletons. And hey. I can assure you, in 2036, paleontologists will be making fun of us for our mistakes. But if we can't laugh at tripods and croc-like bellies, then what can we laugh at?

DinoBlag: Phacops

You heard me. Phacops rana. This is an exciting moment for the blog, as this is the first species featured in a DinoBlag which I actually own a specimen of. Phacops is a classic Devonian trilobite, native not only to North America, but also to Morocco. The specific name is a reference to its eyes, which reminded scientists of the common frog (Rana).

It lived around 400 million years ago in shallow seas, and is a common fossil in many Devonian sediments. It is known for commonly being found in a balled-up position similar to that of the modern pillbug (Armadillidium vulgare). It is the state fossil of Pennsylvania.

Phacops is the state fossil of Pennsylvania, and quite a large trilobite at up to 6 inches in length. Something interesting about its relatives are that they are capable of seeing almost 360 degrees around the animal, which undoubtedly would have allowed it to detect incoming predators.

Tyrannosaurus Species (Also: 50th Post! Whoo!)

(Picture: Which is the tiger? Which is the lion? Where should we draw the line?)

Today, it's easy to tell species apart from one another, even within the same genus (well, generally). We have the luxury of seeing tigers and lions in the flesh, and of seeing their distinguishing characteristics (stripes and manes, respectively). But in paleontology, to the regret of many, things just aren't that simple.

With dinosaurs, we are dealing with something quite different from big cats. These are animals whose living relatives today, crocodiles and birds (you BANDits are in denial!), are very different from their saurian cousins indeed. Of dinosaurs, we have only stripped, petrified bone (except in some very extraordinary and exciting cases, such as mummified Brachylophosaurus and feathered dino-birds from China), which makes it very hard to use characteristics like these to classify them. For examples of living and extinct animals, I will use lions and tigers, and T. rex as my examples for living and extinct animals, respectively.

Any 3-year-old can tell a lion and tiger apart. The lion, Panthera leo, has a magnificent mane and tawny skin. Its legs are relatively well-suited for running, though not as much so as those of the cheetah (Acinonyx jubatus). A tiger, Panthera tigris, is much bulkier than its African cousin, with stouter legs, an orange, striped coat, and a considerable aptitude for swimming. These two animals are so different on the outside, it's hard to imagine clumping them together as the same beast.

But if we take a dip beneath the cats' skin, things become a bit complicated. There are remarkably few anatomical differences between the two, besides the differences in hair and skin, which, one should think, would make the two quite indistinguishable to hypothetical scientists from after the animals in question are long gone. So how can we assume that dinosaurs were any different?

Tyrannosaurus rex is arguably the most famous of all prehistoric creatures. Yet compared to other dinosaurs, it is relatively uncommon. A single species resides within the genus, and has for the century and more that the dinosaur has been known to science. But some scientists insist that tyrannosaurs closely resembling old Rexie are also a part of the genus.

Tarbosaurus bataar is a very close relative of Tyrannosaurus from the Late Cretaceous of Mongolia. There are some small, if appreciable, differences in the skeletons of the two animals, but many paleontologists (palaeontologists?) feel that Tarbosaurus is naught but another species of Tyrannosaurus. Tyrannosaurus bataar would be the name of the dinosaur if it was reclassified. In short, the afforementioned paleontologists want to "clump" Tarbosaurus into Tyrannosaurus.

Some scientists even go so far as to classify Daspletosaurus torosus, considered by some as ancestral to T. rex, as another species of Tyrannosaurus - T. torosus - despite some major differences in skull structure. Where does it end? When does the clumping stop, and poor Das and Tarbo can live in taxonomic peace?

If we can notice these differences in the species even marginally over 70 million years of geologic time, isn't it clear that they were even more different when they were alive? They were probably even more different than lions and tigers (well, maybe not; dinosaurs didn't have hair, after all). If we can't even tell lions and tigers apart in the bone, but can with reptiles which have been extinct for so long, why should these tyrannosaurs be just as closely related?

We frankly don't have the luxury of seeing dinosaurs in the flesh. So who knows? There could have been plenty of Tyrannosaurus species, all as different and distinguishable as tigers and lions. But the thing is, we'll never know, unless some day, we can see the dinosaurs alive. So please: clumpers, please stop clumping! Tarbosaurus and Daspletosaurus are just not Tyrannosaurus.

DinoBlag: Neovenatoridae

One of the more recent developments in the classification of dinosaurs is the 2009 addition of the family Neovenatoridae. The neovenatorids are the last of the allosauroids, relatives of the Jurassic Allosaurus and the Cretaceous giant Giganotosaurus. Neovenatorids range in time from the Early Cretaceous, 128 million years ago, to about 70 million years ago. They are known from South America, Australia, East Asia, and Europe.

Many neovenatorids are characterized by large thumb claws, especially Megaraptor and Australovenator. 7 species across 7 genera are known from this family, placing it in the middle range for diversity among dinosaurs (compare to 9 genera in Tyrannosauridae and 2 in Psittacosauridae).

The type species, Neovenator, is somewhat of an anomaly among the family, being the only species of neovenatorid known outside of the southern regions of the world. It is outclassed only by Aerosteon in size, at 7.5 meters in length. The other species of the family probably averaged somewhere around 4.5 - 5 meters.

Neovenator was described by Martill and Barker in 1996, and the family was described by Benson, Carrano, and Brusatte in 2009.

DinoBlag: Dicraeosauridae

A DinoBlag first: a whole family of dinosaurs. The Dicraeosauridae was a family of diplodocoid sauropods, related to diplodocids such as Diplodocus, Apatosaurus, and Barosaurus. They are, however, distinguished from these dinosaurs by their shorter necks and smaller size. Three species are known of this family thus far: Dicraeosaurus, Amargasaurus, and Brachytrachelopan.

The type species, Dicraeosaurus, was described by Werner Janensch in 1914 for fossils found in the late Jurassic Tendaguru Formation, a fossil formation in Tanzania which also bears Giraffatitan and Kentrosaurus fossils. It is the largest dinosaur in the above diagram, at 41 feet in length. It was named "bifurcated lizard" for the set of small spines on its back.

Another species was not added to the family (named in 1929) until 1991, when the distinctive Amargasaurus was described. It had a set of tall spines running down the length of its neck. At 33 feet, it was smaller than Dicraeosaurus but larger than Brachytrachelopan. It was described by Leonardo Salgado and Jose Bonaparte, from the Cretaceous of Argentina.

The smallest species in this diagram, Brachytrachelopan, was described by Oliver Rauhut et al. in 2005 for fossils also found in Argentina. It had the shortest neck in the family. Indeed, the shortest neck of any sauropod. Its name, "short-necked Pan", in reference to the Greek god of shepherds.

This family was native to the southern continents of Gondwana, and must have migrated here from the northern continents before they broke away from the north, around 140 million years ago, but after the diplodocoids came into existence, 154 million years ago. That is, of course, unless the order Diplodocoidea came into being on the southern continents. Dicraeosauridae is classified either as the most inclusive clade containing Dicraeosaurus but not Diplodocus, or as any diplodocoid more closely related to Dicraeosaurus than Diplodocus.

The diagram at the top was created by Nobu Tamura, and is used here under the GNU Free Documentation License.

And the First Dinosaur of the New Year Is...

(Pictured: Not Texacephale, but its relative Prenocephale)
Texacephale langstoni! This dinosaur was described yesterday from cranial remains found in the Big Bend region of Texas. It has been found to be a relatively pachycephalosaur from the late Campanian in the Cretaceous.

It's helped to rewrite pachycephalosaur taxonomy, too. Classification of this dinosaur has shown that pachycephalosaurs found in Asia, such as Homalocephale and Prenocephale form a monophyletic group. A monophyletic group is determined by whether or not the common ancestor of all members of the group would be considered of that group. For example, the common ancestor of an ostrich and a sparrow would have feathers, wings, and be warm-blooded, and therefore a bird. This means that Aves is a monophyletic group. Whereas the rhino's ancestor is related to horses, an elephant's to seacows, and a hippo's to pigs, which makes the group Pachydermata a non-monophyletic group.

And, surprisingly, analysis of its skull has revived the debate over whether or not pachycephalosaurs could have used their skulls in combat. And here I was, betting on the first dinosaur of 2010 to be yet another theropod.

Happy New Year!

It's 2010! A good new year to whoever may be reading this. Here's hoping that this new decade brings plenty of new dinosaurs into the realm of science, and that maybe, just maybe, we'll see some good dinosaur documentaries (for once)!

Fun With Nomen or: The Taxonomist's Migraine

Taxonomy, the study of naming life scientifically, is an immensely complicated and confusing science, easily confounding enough to baffle any taxonomist, let alone hapless non-scientists who wonder what all the Latin words mean. This is evidenced by the number of names which have been left behind in the proverbial dust over the years.

A nomen dubium (pl. nomina dubia) is a scientific name based off of insufficient evidence to make it a valid name. There are a plethora of these in the scientific archives, more than enough to fill up a thick volume. A nomen nudum (pl. nomina nuda) is a word that sounds like a scientific name, and may indeed have been intended as one, but was never officially published, and as such holds little to no scientific value. A nomen oblitum (pl. nomina oblita) is a name which has not been used scientifically since 1899, after which any junior synonyms take its place.

Below are some of my favorites in that confusing world of dubious, stripped, and forgotten names, and the stories of how they came to be.

*Aachenosaurus - This dinosaur was discovered in the borderland between Belgium and Germany in 1888, and classified as a hadrosaur. Unfortunately for the reputation of its discoverer, Aachenosaurus turned out to be based upon specimens of petrified wood.

*Apatodon - "Deceptive tooth". The label couldn't fit better! When the backbone of this synonym for Allosaurus was found by Othniel Charles Marsh, he thought it was the tooth of a pig.

*Succinodon - Discovered by von Huene in 1941 near Warsaw, Poland, this fossil was attributed to the jaw bone of a titanosaur. However, later studies showed that it was - surprise - petrified wood.

*"Unicerosaurus" - "Unicerosaurus" was the nomen nudum given to a y-shaped bone from Texas, which was used for display at a Creation museum.

*Dynamosaurus, Manospondylus, Stygivenator, Dinotyrannus - All cool-sounding synonyms for Tyrannosaurus. Dynamosaurus, Stygivenator, and Dinotyrannus are all junior synonyms, by Manospondylus was named before Tyrannosaurus. However, since it hasn't been used since 1892, it's a nomen oblitum.

And there's plenty more where that came from. The point being, taxonomy is very complicated, and you should count yourself lucky that you don't have to deal with them more than you do! (Pictured is a nomen dubium, Agathaumas.)

DinoBlag: Giraffatitan

Two DinoBlags in a day? Blasphemy! However, I felt that I should make at least one other update before I logged off. So to that effect, this is the DinoBlag for the huge Giraffatitan brancai. Giraffatitan is known from several specimens which were found in the early 20th Century in Tanzania. It was named Brachiosaurus brancai by Janensch in 1914, but was set apart as a distinct genus by Gregory S. Paul in 1988.

It was somewhat more gracile than the American Brachiosaurus, but still measured at a whopping 82 feet (25 meters) long, 43 feet (13 meters) tall, and weighed around 25 tons (23 tonnes). It lived during the Upper Jurassic, about 145 million years ago, and was an herbivore, grazing from the tallest trees. Though its reclassification has been disputed, a recent study by Michael Taylor showed that almost every bone that was compared was different in some way or another from Brachiosaurus'.

Interestingly enough, most reconstructions of Brachiosaurus are based off of Giraffatitan skull material, giving us the classic high-crested look we're all used to. However, a skull found in the US in 1998 has been shown to belong to a North American Brachiosaurus, and is much more similar to that of the Camarasaurus than of Giraffatitan.

DinoBlag: Megistotherium

The subject of our latest DinoBlag is an animal which is argued to be the largest mammalian land predator of all time, Megistotherium osteothlastes. Megistotherium is known from several specimens from Libya and Egypt, which date back to the Eocene epoch, 24 million years ago.

Megistotherium is a hyaenodontid, a family of the creodonts, which were a group of large, mammalian carnivores, most with builds similar to those of modern dogs and wolves. Megistotherium was named by Robert Savage in 1973; its full name means, "greatest, bone-crushing beast". It grew up to a staggering 13 feet (4 meters) in length, 6 feet (1.8 meters) tall, and weighed around 1.5 tons. Its teeth were designed for shearing and cutting meat.

Even scarier, mastodon bones found not too far off were found with tooth-marks from Megistotherium, suggesting that the beasts killed and ate the mastodons.

CryptoBlag: Mothman

I was just reading through some of my older articles, and realized that I'd promised some cryptozoology stuff on the blog. To that effect, I've added the CryptoBlag as a sister to DinoBlag. For those who don't know, cryptozoology is the study of animals whose existence is, as of yet, unproven by science. Examples include Bigfoot, Nessie, and the Yeti.

The Mothman was spotted between November 1966 and December 1967 in the town of Point Pleasant, WV, which is just across the Ohio River from Gallipolis, OH. It was described as a man-sized creature, shrouded in shadows, with a pair of large wings and two, red eyes, which are usually described as being on its chest. It is described in witness accounts as being capable of swift flight (keeping pace with speeding cars), and only rarely moving while on the ground.

The first sighting of the creature was on November 15, 1966, near an abandoned WW2 munitions plant outside of Point Pleasant. It was seen by a pair of married couples, who were terrified by its appearance and fled back to town. It was sighted again and again up until December 15, 1967, when the bridge over the Ohio from Point Pleastant to Gallipolis collapsed, kiling 47 people. Curiously, sightings dropped off after the tragedy on the Ohio, and since then very few sightings have taken place.

It's worth noting that by several eyewitnesses, after spotting Mothman, were visited by the infamous Men In Black, tanned government agents with a bent for covering up alien sightings (or so the stories go).

Mission: Opossible

Didelphids, the family of marsupials of which the Virginia opossum (Didelphis virginiana) is the only living member, are the only marsupials left in North America. However, recent studies show that North America was once the hub of marsupial activity. In fact, the paradectids, a sister group to the didelphids, are now thought to have been the root of all living marsupials.

Compared with other mammals (except maybe monotremes such as the platypus), marsupials are remarkably primitive. They bear their undeveloped young in pouches, where the infants nurse until they are able to fend for themselves. Even their appearance is prehistoric, as any American with a trashcan can tell you from experience. They almost look as though they belong in the Mesozoic, rather than the modern day.

The news that these primitive mammals originated in North America has been decided based on a skull found in the Eocene Bighorn Basin of Wyoming, USA. Analysis of the skull, and two 30-million-year-old skeletons, shows that the split between opossums and all other marsupials on the planet occurred about 65 million years ago, at the end of the Cretaceous, in North America.

It is presently thought that marsupials migrated from North to South America until the end of the Cretaceous, when the two continents split (until the Pliocene, at least), and marsupials made their way through Antarctica to Australia, as the southern continent, much warmer in those days, is thought to have connected South America and Australia.

Venom!

Surprise, surprise! Recent studies show similarities between the mouth structures of small feathered dinosaurs, such as Sinornithosaurus and others, and those of venomous snakes such as vipers and rattlesnakes. What does this mean? We're not sure yet, but it would seem to suggest that maybe the furry little things weren't so cuddly as you'd think.

If the scientists are to be believed, small predatory dinosaurs like these may have been venomous. Which means that Velociraptor and others would have not only had killer claws, but also a killer bite. (Though, recent studies show, the "killing" claw would have been more suited for climbing than slicing) See also the May, '09 article about venomous Komodos.

DinoBlag: Dryptosaurus

Introducing the brand new segment, DinoBlag which will be replacing the Critter of the segment. The first creature feature (hehe) is the first theropod to be discovered on the North American continent, Dryptosaurus aquilunguis, which was a primitive tyrannosaur.

Dryptosaurus was discovered and named in 1866 by Edward Drinker cope as Laelaps aquilunguis, referring to the Laelaps, a dog of ancient Greek myth. However, it was soon discovered that the name was, as often happens, taken by a genus of mite. It was the first dinosaur to lose its name to a bug, but it certainly was not the last. It was renamed as Dryptosaurus by Othniel C. Marsh in 1877, and the name has, so far, proved valid.

It is thought that Dryptosaurus, one of the dinosaurs endemic to New Jersey, USA, was related to the Early Cretaceous tyrannosaur, Eotyrannus, from England, and it has three fingers on two relatively long front limbs. It is thought that it would have primarily preyed upon the contemporary Hadrosaurus, which was the first dinosaur discovered in the US. Though, due to the rarity of east coast dinosaurs, it is difficult to get a complete picture of Dryptosaurus' diet.

Dryptosaurus was about 20 feet (6.5 meters) long and 6 feet (1.8 meters) tall. It probably weighed a bit over a ton, and was somewhat more gracile than Tyrannosaurus and company. It lived about 70 million years before the present, in the Maastrichtian age of the late Cretaceous.

So, uh...

I'm lazy when it comes to these things, really! Worry not, 3 or 4 fans. I'll get more updates onto the blog here soon.

Scientific Names as Common Names (or Ranting is Fun)

I've decided to resume updating my blog, and the first new addition is this subject which has been on my mind for a while. I'm sure we've all heard of the "Brontosaurus" (explained in an older post here), one of the most popular dinosaurs for a period of decades. Sadly, despite its (admittedly) awesome name, it is not proper for use in scientific circles. Does this, however, mean that it shouldn't be used outside of scientific circles?
Consider this: Despite the fact that we refer to Puma concolor outside of science more often as a mountain lion (or depending on where you live, cougar, catamount, etc.), mountain lion is still acceptable as a common name. Because of this, perhaps 'brontosaur' could be adopted as a common name for sauropods, the long-necked dinosaurs. Indeed, this could extend even farther, to generalizing the term 'dinosaur'. To my other paleo-stricken friends out there, I'm sure that an innocent ichthyosaur or mosasaur being slapped with the term 'dinosaur' is like nails on a chalkboard as, in the strictest manner, they do not belong to the Dinosauria. However! I believe it's possible that 'dinosaur' could be accepted as a common name (like how we call certain animals by names of other creatures today, despite their not being closely related). If this were the context of the word, then perhaps Ichthyosaurus, Mosasaurus, Plesiosaurus, and Pteranodon could all be considered 'dinosaurs'; if not for being part of Dinosauria, then at least for resembling them. Just some food for thought!

Ohaithar

After a lenghthy string of week-long events, computer issues, and general laziness, I have returned to update my paleo blog. Rejoice!

Central Ohio Mineral, Fossil, Gem & Jewelry Show

I paid a visit today to the COMFGJS (That is, Central Ohio Mineral, Fossil, Gem & Jewelry Show), and purchased several new fossils for my small collection, including a few Cretaceous shark teeth, a fragment of Glyptodon armor, and a real Spinosaurus tooth (a similar tooth shown above). All in all, an exciting and delightful experience. I recommend this show for anyone in Ohio or, indeed, anywhere else who is interested in such things.

Coo-coo!

In keeping up with all the missing-link hubbub of recent days, I'd like to announce the discovery of the missing link between a man and a loon. Ever heard of initial bipedalism? No? How about the AAH, or aquatic ape hypothesis? Didn't think so. However, Francois de Sarre, a French paleontologist, seems rather convinced. According to his theories, he believes that all tetrapods are descended from a proto-water-ape that lived millions of years ago. Understandably, his theory isn't extremely popular with the scientific community, but it is fun to read about.

http://scienceblogs.com/tetrapodzoology/2008/03/initial_bipedalism.php

"Dangerous Bacteria" My Rear!

Scientists have recently taken a closer look at the mouths of Komodo dragons, and boy, were they surprised! As it turns out, the hypothesis about bacteria killing the dragons' prey was nothing but a "fairy tale". Scientists discovered that the Komodo dragons in fact have a primitive venom-delivery system, akin to that of the only formerly-known to be venomous lizard, the Gila monster. This discovery implies that the dragons' close relative, the "Megalania" prisca, might also have had the same venom, which would make it the largest venomous animal known to science. Photo courtesy of National Geographic.

http://news.nationalgeographic.com/news/2009/05/090518-komodo-dragon-venom.html

http://dml.cmnh.org/2009May/msg00151.html

Sauropods - Not So Stiff, After All

As it turns out, sauropod dinosaurs may not have had necks as stiff as recent studies have hypothesized. This has added fuel to the old theories about sauropods browsing in the trees like oversized, saurian giraffes. The above picture is by Mark Witton.

http://scienceblogs.com/tetrapodzoology/2009/05/sauropods_held_necks_erect.php

Dinosaurs Might Have Dug Cheese

Erm, well... okay. That might be a bit of a stretch in the title. But recent discoveries have uncovered the first Mesozoic fossils from my birth state, Wisconsin. Samples inclue crocodile teeth and leaves dating back to the Cretaceous period. Regrettably, those pesky glaciers seem to have carried away any evidence of dinosaurs themselves, but we can only hope that one day they may be found.

http://www.jsonline.com/news/wisconsin/44755302.html

Eeew. But, Cool!

http://dml.cmnh.org/2009May/msg00079.html

As it turns out, aquatic snails may have used dino dung as shelter upon land. I'm not sure if I should be disgusted or astounded.

Dinosaurs May Have Survived After Impact

New evidence from rock strata in Utah and Wyoming suggests that some species of dinosaurs might have dwindled on for as many as 500,000 years after the Chicxulub impact event supposedly wiped them out. Though this may not mean much, it does offer credence to theories of extant dinosaurs throughout the world.

Holy Smokes!

Too much came out in one week. Curse my laziness. I'll have to cram all the new info into a few short posts, so bear with me as I attempt to tackle all the important news that came out over the past week.

Critter of the Week, 5/29/09: Schinderhannes

No, not the German criminal. Schinderhannes bartelsi may soon prove to be one of the more important fossil discoveries in arthropod science. Schinderhannes might be no different from any other anomalocarid - if it hadn't lived 100 million years after its close relatives had supposedly died out. While it was presumed for some time that the Anomalocarididae had gone extinct at the end of the Cambrian, about 510 or so million years ago, the 390 million-year-old Schinderhannes dates from the end of the Devonian. Additionally, it offers some odd clues to arthropod evolution - it seems to be transitional between anomalocarids and true arthropods. Though scientists still don't know quite what to make of this, it remains an interesting species nonetheless. As seen in the picture above, this genera has a body similar to that of trilobites and other early arthropods, but a head and mouth almost identical to those of Anomalocaris, as well as hard protrusions similar to those of Hurdia, another Cambrian anomalocarid.

Le Gasp! 'Ida' Shocks Scientists

If you're wondering, 'Ida', whose skeleton is shown at the right, is a 47 million-year-old Darwinius masillae, a species of primitive primate. It is considered by many scientists to be one of many 'missing links'; they believe that Darwinius lived some time near when more primitive primates such as lemurs and lorises branched off from more advanced primates, including monkeys, great apes, and, by extension, us. Does that mean anything? Probably not. But it gives us an excuse to hype up the media and gape at the wonderfully-preserved specimen from the Messel Shale (see right).

Critter of the Week, 5/20/09: Deltadromeus

Why am I replacing Critter of the Day with this segment? I'm a slacker. The very first Critter of the Week is Deltadromeus agilis, a medium-sized carnivore from the Cretaceous of North Africa. Deltadromeus is a member of a little-known family of ceratosaurs known as the Noasauridae. This family is characterized by their slender builds, which differentiate them from their abelisaurid cousins. Though Deltadromeus' skull has never been found, it is known from a few, relatively complete skeletons. It may have been a swift runner, and certainly would have to have been, to avoid its larger contemporary, Carcharodontosaurus. It was first described by Sereno et. al in 1996, and may be a junior synonym of the mysterious Bahariasaurus.

Critter of the Day, 5/14/09: Yangchuanosaurus

Yangchuanosaurus shangyouensis is an oddly-named theropod with an equally odd historical taxonomy. Like many other large carnivores, it was once thought to have been a megalosaurid (theropods more closely related to Megalosaurus than to spinosaurids), but was later assigned to the Sinraptoridae, a family of primarily Chinese carnosaurs which also includes Sinraptor, Metriacanthosaurus, and possibly Gasosaurus. It is believed to have filled a niche similar to that of its American cousin Allosaurus, which lived at the same time. If this is the case, it would have hunted down sauropods, possibly in small packs, occasionally running forward and inflicting large cuts, forcing its victims to bleed to death. It could have grown up to 35 feet (10 meters) long, and could have weighed as much as almost four tons. It was named in 1978 by Dong, et. al.

Critter of the day, 5/13/09: Daspletosaurus

Today's creature seems at first to be so close to Tyrannosaurus, that some scientists have hypothesized that it may be rexy's direct ancestor: Daspletosaurus torosus. This large tyrannosaurid lived between 80 and 73 million years ago. It was relatively robust, with a thick skull and stout legs. It coexisted with the smaller tyrannosaur Gorgosaurus libratus, and so it is currently believed that they occupied different dietary niches. It's known that Gorgosaurus probably fed mostly on hadrosaurs (duck-bills) like Parasaurolophus and Edmontosaurus, but it is still unclear at present exactly what Daspletosaurus's diet was. It was a relatively large tyrannosaur, at over 30 feet (9 meters) long. It was described by Russell in 1970.

Critter of the Day, 5/12/09: Gigantoraptor

Gigantoraptor erlianensis is one of the odder discoveries of recent years, both the largest oviraptorosaur (oviraptors) known to science, and the largest dinosaur currently thought to have posessed feathers in any significant number. Like other members of its family, Gigantoraptor would have been omnivorous, feeding on both plant matter and smaller animals. At a whopping 26 feet (8 meters), it is one of the larger theropods to have come from the Upper Cretaceous of Mongolia and China. It was described by Xu, et. al in 2007, and the above picture is by Luis V. Rey.

Critter of the Day, 5/11/09: Mapusaurus

Mapusaurus roseae was a large carcharodontosaurid (carnosaurs which include Carcharodontosaurus and Giganotosaurus) which dates from the Late Cretaceous, about 80 million or so years before the present. This is one of several varieties of large, carnivorous dinosaur which have been found in bone beds; the presence of individuals of several growth stages in the same place both gives us a more complete image of this genus, as well as a hint that it may have hunted in packs. It's speculated that, like other carcharodontosaurs, it may have charged in at sauropods to take a bite or slash, retreated, and repeated the process until its prey died of shock or blood loss. It was described in 2006 by Rudolfo Coria and Phillip Currie.

Trilobites - Not Exactly Tiny!

A recent discovery in a Portuguese quarry has given us many new specimens of large trilobites, including the species Ogyginus forteyi and Hungeoides bohemicus, which indicate that more trilobites than we'd previously thought grew up to large sizes. Though throughout much of the region the average size of trilobites is only 10 centimeters, the average trilobite in the quarry is estimated at an unverified 30 centimeters long. The 2000 Isotelus rex specimen from Canada still has the crown for the largest trilobite currently verified, at 28 centimeters, but several specimens from the quarry are at least two centimeters long, and fragments have been found of what could prove to be a 90 centimeter specimen, which would be the largest trilobite on earth. The fossils date from around 460 million years ago, during the Ordovician period, when Portugal was near the South Pole.

Critter of the Day, 5/10/09: Tupuxuara

Two pterosaurs in as many days? For shame, I know. I can't help it if these guys are really interesting. The spotlight critter today is Tupuxuara longicristatus. Like its distant relative Tapejara, which was made famous in Walking With Dinosaurs, Tupuxuara lived in Brazil during the early Cretaceous. Its most distinguishing feature is its odd, swept-back crest. Its closest relatives are the azdarchids, the family of pterosaurs which includes Quetzalcoatlus and Hatzegopteryx. The first specimen was identified by Kellner & Campos in 1988.

Critter of the Day, 5/9/09: Nyctosaurus

Gracing my page with its wonderfully odd crest today is Nyctosaurus, a pterosaur closely related to the more famous Pteranodon. Even though it was named by O. C. Marsh way back in 1876, it was not recognized as posessing its large crest until quite recently. The function of the crest is unknown, but it may have been used either for display or steering. This flying reptile lived at the very end of the Cretaceous, 65 million years ago, throughout the Western Interior Seaway which ran through North America.

Critter of the Day, 5/8/09: Alamosaurus

Scientists currently consider it very unlikely that Alamosaurus sanjuanensis will be host to a battle between Texan soldiers and the Mexican Army, so visiting a mounted skeleton in a museum is probably perfectly safe. In all seriousness, though, this Upper Cretaceous titanosaur (southern long-necks; last known sauropods) was actually not named after the Alamo in San Antonio, but after the Ojo Alamo Formation in New Mexico. Confusing, huh? This sauropod is the only known titanosaur to have occured in North America, as most members of that group of sauropods are known only from localities which were once part of the southern supercontinent of Gondwana, such as South America, Africa, India, Madagascar, and southern Europe, though some forms have also been found in Asia. This dinosaur was named by Gilmore in 1922, and played a confusing game of taxonomical hopscotch before finally being placed with the titanosaurs.

Critter of the Day, 5/7/09: Nedoceratops

A strange name for a strange dinosaur - Nedoceratops hatcheri, formerly "Diceratops hatcheri", was renamed in 2007 by Ukrainsky, the former name having been coined by Richard Swan Lull. This poor ceratopsian (Triceratops and its ilk) was yet another incident of a dinosaur's name being changed, the name having been occupied by a bug (yes, a bug. See also, Dryptosaurus, Mononykus), in this case those pesky hymenoptera (assorted oddball bugs including bees and ants). Though on first inspection it is quite similar to its close cousin Triceratops (in fact, some scientists think that Nedoceratops is the closest relative of the more famous ceratopsid), this species differs from its larger, more popular relative by the fact that rather than a nose horn, it has a rounded lump similar to that found on the primitive ceratopsian Zuniceratops.

Critter of the Day, 5/6/09: Appalachiosaurus

Today's featured critter: a little beastie called Appalachiosaurus montgomeriensis from the Upper Cretaceous of Alabama. This tyrannosaurid (T. rex's dysfunctional, extended family) is one of the most complete dinosaurs known from the American South. This 23-foot (7 metres, for our cousins across the pond and every other country on the planet) tyrannosaur was named by Thomas Carr (et. al) in 2005, and probably preyed upon and ate hadrosaurs and other herbivores, probably stopping to scavenge some dinosaur corpses along the way. Considering that it lived near the coast, there's also the possibility it could have taken to a seafood diet, maybe scavenging beached mosasaurs of plesiosaurs (not exactly fine cuisine).

Critter of the Day, 5/5/09: Gojirasaurus

No, this dinosaur has never been known to raid Tokyo. No, it probably would not take an Oxygen Destroyer to kill. But that certainly is the image that Kenneth Carpenter wanted to elicit when he named this dinosaur in 1997; Gojirasaurus quayi named for the big G himself, is the largest coelophysid (early, primitive theropod) currently known to science (don't confuse with largest coelophysoid, Dilophosaurus). This 18-foot dinosaur probably wasn't as fast as its smaller cousin Coelophysis, but it was still probably a rather fast, formidable hunter.... No, no atomic beams, either.

Critter of the Day, 5/4/09: Olorotitan

Weird-looking guy here, huh? I'll say! Olorotitan arharensis is quite the odd hadrosaur (duckbilled dinosaur); discovered in the Amur region of Russia, and described in 2003 by Pascal Godefroit (et al.). It is the most complete lambeosaurine (crested hadrosaur) known at present from outside of North America. Some of its more famous relatives include Parasaurolophus, Corythosaurus, and Lambeosaurus. Its most distinguishing feature is its crest, which takes on a shape unlike that of any other lambeosaur, and its strange appearance has caused scientists to wonder just how diverse the hadrosaurs really were.

Critter of the Day, 5/3/09: Uintatherium

Thought I only had a dinosaur fetish? Don't think I'd forget our Cenozoic buddies, the extinct mammals. I love those guys! This one in particular: Uintatherium anceps. This dinoceratian (a group of large, extinct mammals, presumably hairless) mammal lived during the middle of the Eocene Epoch in the Paleogene Period (formerly the Tertiary) of North America. This big guy was first discovered at Fort Bridger, Wyoming, and was named by famed paleontologist Joseph Leidy in 1872. Its six horns were apparently used as a display to the opposite sex, and the tusks in its mouth would have been useful for detering hyaenodont predators, a variety of carnivorous mammals from the same time and locality. The above picture was painted around 1920 by Heinrich Harder.

Critter of the Day, 5/2/09: Acrocanthosaurus

Today's daily critter: the mighty Acrocanthosaurus atokensis! This 40-foot carnivorous carnosaur (check up on the new definition - any dinosaur more closely related to Allosaurus than birds. It no longer means just any large carnivore) sported what is presumed by most to be a flashy sail (some guys think it supported a bison-like hump. Crazy bovinophiles). No one can seem to agree on whether this carnosaur was a very late Allosaurid or a northern Carcharodontosaurid (huge, southern theropods and voracious hunters of sauropods, or so our current understanding is), but the fact remains that it was quite a dangerous-looking beastie. The original specimen was found in Atoka County, Oklahoma, from which its species name was derived, and was then named in 1950 by J. Willis Stovall and Wann Langston, Jr. Due to its large dorsal spine, it was classified for some time with the spinosaurids. Additionally, the above picture (I think it's by Dmitry Bogdanov, but Wikipedia may have lied to me) is supremely kickass.

Guess Who's Back? Bronto's Back (Maybe)!

For you laymen out there who wonder what "Brontosaurus" would be brought back from, it's probably worth noting that, despite its frequent use in popular culture, the name "Brontosaurus" was merged into the name Apatosaurus way back in 1903 (you heard me. Still in use 106 years after it was 'deleted' from taxonomy books). The reason lies with the famous Bone Wars of the late 19th Century, between famed paleontologists Edward Drinker Cope and Othniel Charles Marsh. These two bitter rivals raced throughout the American West, going to extreme lengths (shoot-outs, stealing fossils, breaking said fossils, etc.) to name more species of dinosaur than each other. In 1877, Marsh named Apatosaurus ajax, the type species of the new genus Apatosaurus. Two years later, in 1879, he named another new species, "Brontosaurus" excelsus. Marsh could never have known that this second genus would soon become the bane of every paleontologist's existence. In 1903, 24 years later, Elmer Riggs pointed out the obvious similarities between the two, and put out buddy "Brontosaurus" into the earlier genus, christening it Apatosaurus excelsus. Obviously, the public was not told about this development. As of May 2009, there are four accepted species of Apatosaurus: A. ajax, A. louisae, A. excelsus, and A. parvus (formerly Elosaurus) In this frame of time, the Diplodocidae family of dinosaurs (the family that includes Apatosaurus and Diplodocus) has continued to cause massive headaches for dinosaur scientists (See Amphicoelias, Eobrontosaurus, etc.). And they aren't finished yet! Recent studies have shown that another diplodocid long-neck, Supersaurus, is more closely related with A. ajax and A. louisae than either are to A. excelsus (Bronto). By ICZN regulations, this should mean that A. ajax and A. louisae and A. excelsus should be placed in separate genera; and by the same ICZN rules of naming priority, "Brontosaurus" would be the name used for a new genus. I realize that as a chronic 'splitter', I may be a bit biased, but it does seem that the taxonomical rules obligate that "Brontosaurus" be brought back as a genus name. Feel free to discuss this, argue with it, or support it in the comments. I'm open for ideas here. xD

Despots, Ornithos, and Heteros. Oh, my!

The world of paleontology is abuzz these couple of months over several discoveries from the rich fossil beds of China - three new genera of Lower Cretaceous dinosaurs have been uncovered: Xiongguanlong, Beishanlong, and Tianyulong (what's up with all the longs, any way?); a tyrannosauroid, ornithomimosaur, and heterodontosaur, respectively. These three are quite important in modern dinosaur science, for reasons explained here. Firstly, Xiongguanlong is yet another of that important branch of dinosaurs which eventually led up to the great Tyrant himself, the fabled T. rex. This long-snouted primitive tyrannosaur has garnered the coining of a new 'main-stream' nickname for the early rex wannabes: "despots", just one step below a proper tyrant. Secondly, an interesting, though regrettably incomplete, skeleton has been found of Beishanlong, a large ornithomimosaur. Though known only from arms and a few fragments, it is estimated to be the largest ornithomimosaur found to date, excluding possibly Deinocheirus, the mysterious theropod known only from a pair of six-foot arms. Lastly, and perhaps most importantly, is Tianyulong, a heterodontosaur which has (gasp!) feathery body coverings. You heard me! Feather science as we know it has been turned on its head by this discovery, which could possibly mean that the common ancestor of ornithischian (bird-hips, e.g. Triceratops, Parasaurolophus, Ankylosaurus, Stegosaurus) and saurischian (lizard-hips, e.g. Tyrannosaurus, Velociraptor, Plateosaurus, Apatosaurus) dinosaurs had feathers, which, by extension, puts forward the possibility that most, if not all dinosaurs, would have had at least some feathers on their bodies at some point in their lives. Though hints of this were heard when the ceratopsian Psittacosaurus was found with feather-like bristles a few years back, only now are we starting to get clues that dinos were a bit fuzzier than we previously thought. Keep your eyes peeled in the coming years for downy brachiosaurs and fluffy stegosaurs.