February 22, 2010

Reconstructing Ptychodus

6:33 pm

Today at Laelaps, Brian Switek posted a summary of new research (Shimada et al. 2010) on the Cretaceous shell-crushing shark Ptychodus (tie-KOE-duss). Like many fossil sharks, Ptychodus is primarily known from teeth—usually isolated but occasionally found in their arrangement in life: packed together in rows that would have made its jaws look a little like two cobblestone streets set in opposition to each other. No doubt many Cretaceous shellfish met a crunchy end ground between such pavements.

Outside of the inside of its mouth, however, little is known about the appearance of Ptychodus. The researchers behind the new study propose that it might have been something like a modern nurse shark (Ginglystoma cirratum), which also finds most of its food in the along the bottoms of tropical seas.

I was happy to read this because several years ago I had a similar thought and worked up a sketch of a nurse shark-like Ptychodus, complete with big pectoral fins, little eyes and speculative whisker-like barbels for sensing prey beneath the sediments.

The enigmatic durophage Ptychodus as a nurse shark analogue.

About a year after I put together that sketch, my friend Mary Sundstrom expanded on the sketch to create a dynamic, shell-crunching reconstruction for a web project at the day job:

Painting of Ptychodus based on the previous sketch, by Mary Sundstrom, 2005.

—Matt Celeskey.

February 12, 2010

More Bistahieversor

9:31 am

Tom Williamson, one of the scientists who described the new tyrannosaur Bistahieversor sealeyi, has written an excellent article for the New Mexico Museum of Natural History and Science website on the discovery and interpretation of “The Bisti Beast”.

—Matt Celeskey.

January 30, 2010

Bistahieversor sealeyi

3:34 pm

Congratulations to Drs. Carr & Williamson on the publication of “The Bisti Beast,” whose description is the cover story in this month’s Journal of Vertebrate Paleontology.

  • New Dinosaur: Bistahieversor sealeyi
  • Pronounced: bis-tah-he-ee-VER-sor SEE-lee-eye
  • Name means: Sealey’s Bisti destroyer (Paul Sealey discovered the fossils in the Bisti/De-na-zin Wilderness Area)
  • Named by: Carr and Williamson 2010
  • Relations: Tyrannosauroid, a group that includes Tyrannosaurus rex and its not-too-distant relatives
  • Location: Northwest New Mexico, United States of America
  • Age: Late Cretaceous (Campanian), ~73,000,000 years old
  • Length: ~9 meters (29 feet)
  • Info: Two fairly complete skeletons of a new type of New Mexican dinosaur are helping to fill in gaps in the evolution and distribution of tyrannosauroids, the group of dinosaurs that includes T. rex and its fairly close relatives.
  • Tyrannosauroid fossils have been known from southwestern North America for over 100 years, but mostly in bits and pieces—isolated bones and teeth or, at best, incomplete skeletons of uncertain identity (see Carr & Williamson 2000 for a good overview). Traditionally, researchers have assigned these fossils to well-known tyrannosauroid genera like Albertosaurus or Daspletosaurus, whose more complete remains were originally found further north in Wyoming, Montana, and Alberta.
  • Thanks to recent discoveries, the southwest now has a tyrannosaur all its own. Bistahieversor is the new name given to a complete skull and (mostly unprepared) skeleton from the Bisti badlands of northwestern New Mexico. Its skull and jaws display a healthy list of detailed anatomical characters that distinguish it from all other tyrannosauroids, including a complex joint between the nasal and frontal bones on top of its skull, and a unique hole above its eye. Other tyrannosaur remains from northwest New Mexico, including the partial skull and skeleton of a juvenile, appear to be specimens of Bistahieversor as well.
  • Images:
    NMMNH P-27469, holotype skull and jaw of Bistahieversor sealeyi
    Photograph by David Baccadutre, New Mexico Museum of Natural History and Science.


  • NMMNH P-25049, incomplete skull and skeleton of juvenile Bistahieversor sealeyi
    Both these specimens are on display in the New Mexico’s Seacoast hall of the NMMNHS.

  • Main Reference: Carr, Thomas D. and Williamson, Thomas E., 2010 Bistahieversor sealeyi, gen. et sp. nov., a new tyrannosauroid from New Mexico and the origin of deep snouts in Tyrannosauroidea. Journal of Vertebrate Paleontology, vol. 30 (1), pp. 1–16. doi: 10.1080/02724630903413032
  • Additional Reference: Carr, Thomas D. and Williamson, Thomas E., 2000 A review of Tyrannosauridae (Dinosauria, Coelurosauria) from New Mexico. New Mexico Museum of Natural History and Science Bulletin 17, pp. 113–145.
  • Elsewhere on the web:

—Matt Celeskey.

April 17, 2009

Rocky Mountain Dinosaur Resource Center

7:47 pm

Tylosaurus skeleton at the Rocky Mountain Dinosaur Resource Center
The monstrous skeleton of Tylosaurus proriger looms over visitors entering the Prehistoric Ocean room at the Rocky Mountain Dinosaur Resource Center.

On my way back to Albuquerque from the WIPS Symposium, I made a detour over to Woodland Park, Colorado, to check out the Rocky Mountain Dinosaur Resource Center. This “new species of museum” (according to its tagline) was founded by Mike and JJ Triebold, of Triebold Paleontology Inc., and Mike was gracious enough to come in on a Sunday to give me a tour of the place.

Mike Triebold with the cast of a giant coelurosaur track
Mike Triebold with a cast of a concretion that had formed within the footprint of a giant coelurosaur.

Mike explained that most of the skeletons on display were casts of specimens that he and his team had molded and mounted (and in many cases, collected and prepared to boot). The displays are constantly changing, as the reconstructed (cast) skeletons are purchased by museums and other collectors, and new skeletons are prepped, cast, & put out for display. In the 20+ years the Triebolds have been in this business, their team has put together some spectacular skeletons:

Juvenile Hadrosaur at the RMDRC
Juvenile Edmontosaurus. Behind and to the left is a larger Edmontosaurus. A Tyrannosaurus rex looms over the scene, and the pachycephalosaur Stygimoloch can be spotted in the background as well.

Conchoraptor gracilis at the RMDRC
Conchoraptor gracilis, nicely showing off the robust oviraptor furcula (wishbone).

Dramatic mosasaur mount at the RMDRC
One of my favorite mounts was this dramatically serpentine mosasaur Platecarpus

Dueling Pachycephalosaurus at the RMDRC
Dueling Pachycephalosaurus—these two have been reconstructed from “Sandy”, the most complete pachycephalosaur specimen known from North America.

I have to say I was quite impressed by what I saw during my visit. The mounts were dynamic and did a good job of showing off the range, skill, and productivity of the center’s staff. The large, open halls packed with skeletons & fossils felt a bit like a mix between traditional museum exhibits and a showroom floor, which I suppose is not an entirely inaccurate description. In some ways (none bad) I felt the crowding of the casts on display made the RMDRC feel a bit like an old cabinet of curiosities, with a desire to show off a great quantity and diversity of objects—in contrast to the current museum practice of calling carefully-picked specimens into the service of a grand idea. That said, I’m curious to see how the RMDRC handles themed exhibits like their newly opened Darwin and Dinosaurs, which was still being assembled during my visit.

In addition to the exhibits, there were a couple other aspects of the RMDRC that are worth a mention: First, the floor staff was extremely courteous, helpful, and informed (something I noticed even before I met Mike for the tour). Second, the Prehistoric Paradise gift shop was extremely spacious and well-stocked, something I’m always happy to see. And finally, in the time it’s taken me to get this post written up, I’m happy to see that Anthony Maltese has started posting a blog from the RMDRC paleo lab, so you can get a glimpse of the specimens they’re working on and other behind the scenes happenings at the Center.

—Matt Celeskey.

March 1, 2009

New PalaeoArt Carnival – Art Evolved

12:28 pm

A new internet carnival for Palaeo-Art, ART Evolved, kicked off today with its first themed gallery. Check out the work of several different paleoartists as they interpret the Ceratopsia. Nice Work!

—Matt Celeskey.