Tuesday, November 25, 2014

Laramidian Endemism, Part 2

Last week we saw that, during a good portion of the Late Cretaceous, North America was divided into two unequal halves by the shallow Western Interior Seaway (WIS). Those dinosaurs on western Laramidia were boxed between mountains to the west and the fluctuating coastline of the WIS to the east. They lived on a narrow, vertical strip of land running from Alaska’s North Slope to Mexico. On the other hand, everybody had beachfront property. We can’t say much about Appalachia’s Mesozoic composition, as much of its fossil-bearing rocks were destroyed by the last Ice Age. However, tyrannosaurs and hadrosaurines who were isolated prior to the formation of the WIS evolved along different lines than their western relatives. Dryptosaurus and Appalachiosaurus are the island continent’s aberrant tyrannosaurs. Hadrosaurus and a few potentially dubious genera (Lophorhothon, Hypsibema) represent the area’s hadrosaurine population. It’s ironic that, despite the area’s drastic surface area deficit, Laramidia is ridiculously rich in dinosaur fossils whereas Appalachia is not at all.

Monday, November 10, 2014

Laramidian Endemism: Part 1

Every few years, the wife and I will spend Christmas away from Alaska with her family, in Kansas. Now, the Sunflower State may not be the most exciting place to spend the holidays, but it's usually warmer than it is in Anchorage. It's also, from my point of view, a lot more geologically interesting. Now, of course, Alaska is home to about a million mountain ranges, glaciers, and volcanoes. Indeed, my state is largely a conglomeration of chunks of continental crust, earthquakes, and volcanic activity. In its own way, Alaska is the MOST interesting state, geologically speaking. But Kansas is basically made of limestone and chalk. Alaska's Mesozoic fossil record is only impressive when you look past the fact that it is made up of hundreds of bits, pieces, and chunks of bone.

Tuesday, November 4, 2014

Deinocheirus > Spinosaurus

There’s a new giant, sail-backed, piscivorous theropod in town.

Just a month after Ibrahim et al. (2014) revealed their new interpretation of Spinosaurus aegypticus, Lee et al. have done one better: they've published a description of Deinocheirus mirificus, one of the most mysterious dinosaurs ever found. For those not keeping score at home, Deinocheirus was discovered in 1965 during a Polish-Mongolian expedition into the southern Gobi Desert. Unfortunately, all that was found was a pair of enormous arms—indelibly seared into the minds of every man, woman, and child who opened a dinosaur book over the next forty years. It was pretty easy to see that Deinocheirus was an ornithomimid, but it must have been absolutely enormous. It wasn't until 2006 and 2009 that more skeletal material was discovered—both in the field and in a private collection. For more on this, Ed Yong and Brian Switek have fascinating write-ups about the discovery and its history.

Monday, October 20, 2014

Taxonomic Messes

In his recent Princeton Field Guide to Dinosaurs, Greg Paul did something interesting: he sank most of the Centrosaurinae into Centrosaurus. Thus, instead of Styracosaurus albertensis, you now have Centrosaurus albertensis. Where once there was Pachyrhinosaurus lakustai, there is now only Centrosaurus lakustai. This seems ridiculous on the face of it, but Paul's justification is not entirely off-kilter: he surmises that the Centrosaurinae exhibits as much or less variation than is found between different species of Varanus. But that comparison is, in itself, completely arbitrary. The taxonomy of living animals--and especially living reptiles--is dictated by an entirely separate group of specialists. If paleontologists were in charge of Varanus, it might well be divided into separate genera. Herpetologists (and Greg Paul) are especially fond of subgenera, whereas as I believe that subgenera are confusing and unnecessary.

Sunday, October 12, 2014

Place Name-o-saurus

Albertosaurus, a tyrannosaur from Alberta, in case that wasn't clear.

All of these fossil animal names have something in common. Can you guess what it is?

Albertosaurus, Albertaceratops, Albertonykus, Albertonectyes, Edmontosaurus, Edmontonia, Agujaceratops, Coahuilaceratops, Judiceratops, Utahraptor, Utahceratops, Alaskacephale, Sinosauropteryx, Sinornithosaurus, Sinovenator, Sinocalliopteryx, Sinornis, Sinoceratops, Huaxiagnathus, Huaxiaosaurus, Qianzhousaurus, Zhuchengceratops, Zhuchengtyrannus, Montanoceratops, Argentinosaurus, Nigersaurus, Aegyptosaurus, Brasilotitan, Gondwanatitan, Panamericansaurus, Gobisaurus, Afrovenator, Antarctopelta, Europelta, Europasaurus, Hungarosaurus, Hatzegopteryx, Santanadactylus, Santanaraptor, Santanachelys

Monday, October 6, 2014

Spinosaurus-world Problems

Spinosaurus aegypticus, lord of the Kem Kem river system.

September 12th saw the publication of Ibrahim et al.’s new reconstruction of Spinosaurus aegypticus, surely one of the most famous and mysterious of all dinosaurs. The authors designate a neotype, assign a bunch of previously indeterminate material to S. aegypticus, synonymize “Spinosaurus maroccanus” and “Sigilmassassaurus brevicollis” into S. aegypticus, and offer up a bizarre interpretation of the whole animal. No longer confined to wading in rivers and snatching up fish a la Suchomimus, Spinosaurus is now a proper semi-aquatic dinosaur that the authors compare to early whales. Aside from being published in Science, National Geographic appears to be paying the bills and fabricated a massive skeletal reconstruction and life-size model. As can be expected, there was much media fanfare surrounding the publication and public unveiling.

Monday, September 29, 2014

Return of the Mack

Hi, I'm Zachary Miller. You may remember me from such paleo-themed blogs as When Pigs Fly Returns and Alice's Adventure Through the Windshield Glass. The last time I blogged was June 24, 2012, and lately I've been itching for a comeback. I'm not sure what sparked this resurgence. Certainly, my Secret Project--which I'll write about later--was a catalyst. But I've been more involved in the paleoblog sphere lately, popping up in the comments at Phenomena, Tetrapod Zoology, and even io9 of all places. I've gotten back into the literature in a big way, largely due to my Secret Project, but the discovery that my professorial wife has access to a whole host of online journals means that I'm not begging for papers quite as much as I used to, which is A Good Thing.

Just over three years ago, I had a brain abscess that almost killed me (from what I'm told). While I was not left with any permanent physical impairments, my artistic streak/desire was completely lost. I used to carry a sketch pad with me everywhere I went, doodling every day, and drawing things for When Pigs Fly Returns. Those days are sadly behind me. But my new love is writing (and podcasting). Writing is not necessary a "new love," but I've gotten better at it. I like to think I've honed my craft. Fellow Alaska paleoartists Scott Elyard and Raven Amos just put up a new ceratopsian-theme art show (Shields & Spears) and while I didn't really contribute artistically, I did produce information panels that people seem to like. If you're in Anchorage during the month of October, you should really check the show out--it's at the Yak & Yeti Cafe next to Title Wave in the REI mall.

The next three years were incredibly tumultuous in terms of health. As you may already know, I have Cystic Fibrosis, and the abscess touched off a host of respiratory infections that led to my being hospitalized many times and falling into a state of depression. The past year has seen my physical and mental health stabilize. Now, I can devote my time to reading about paleontology and informing you, the readers, about what I find interesting. While paleontology news will be the main thrust of the content, I intend to cover a wide range of topics within paleontology. My first "official" post will be about the new Spinosaurus paper that just came out, and my second will be about the intellectual bankruptcy of naming fossil organisms after the places they were found.

So a variety of topics, methinks. I hope you enjoy reading the blog as much as I enjoy writing it! You can follow me on Twitter @zmiller1902 and leave comments here on this blog. If you need to get in touch with me by email, I'm pretty sure my email is linked somewhere on this website, since my Gmail login is required to get into this new blog.

See you around the paleo-sphere!