Tuesday, February 22, 2011

Tyrannosaurus as obligate scavenger?

A new paper in Plos One, from researchers at the Montana State University Museum of the Rockies, once again suggests that Tyrannosaurus rex was primarily a scavenger. The hypothesis has been around for some time and was originally put forth by Dr. John Horner, one of the authors on the new paper.

There has been much back-and-forth about whether T. rex was primarily a predator or scavenger. Just a month ago another study suggested that T. rex had to be a predator based on competition with smaller predators. (you can read a good critique of that paper here)

I am an arm-chair paleo-enthusiast so I don't know all of the intricacies of these studies. Likewise I don't really care whether T. rex was stricly a predator or scavenger (personal opinion is that it probably did a little of both as opportunities presented themselves). However, this new study raises a few questions for me.

Paleontologists have worked very hard to establish a well-supported relationship between dinosaurs and birds and yet the researchers in the paper use the mammal predator-prey relationships of the African Serengeti ecosystem as a model for comparison. While we know that dinosaurs were probably warm-blooded to some extent, their metabolic systems are not fully understood and they may have achieved that warm-bloodedness in a manner unlike mammals and more comparable to birds, or a metabolic system between that of more primitive archosaurs, like crocodilians, and modern birds. As a result, it seems to me that modern predatory birds may be a better model for understanding the context of predator-prey relationships and inferring feeding behavior.

I'm sure others have more questions regarding the methodology and conclusions of this paper. At any rate, any good research paper should generate as many questions as it addresses. While I doubt there will ever be a conclusive determination made regarding the feeding behavior of Tyrannosaurus rex, this and other future papers will generate new ways of thinking about fossil evidence.

photo: T. rex vs. Triceratops photo by Casey Tucker, Wild Auk Photography

Collections Matter

One of the big problems facing many collections-based facilities, like museums and libraries, is the limitation of space as collections grow. Some institutions realize the value of their collections and work to create greater storage space. Other institutions, often led by short-sighted leaders not familiar with collections-based work, often simply begin discarding parts of their collections to make space.

Two recent news items illustrate the importance of preserving collections materials.

First, the Washington University library has recently announced the discovery of quite a few of Thomas Jefferson's books. The books are thought to have been sold to settle Jefferson's debts, but could contain important personal writings of the former president that might provide more insight into him.

Second, as part of a move to a new location the Grant Museum in Great Britain has re-discovered a number of valuable specimens that had been misplaced over the years. However, the most significant discovery was that of a partial skeleton of the extinct Dodo (Raphus cucullatus). The bones were mistakenly thought to be crocodile bones.

Mistaken identification of significant museum specimens occurs regularly. For example in one museum a pair of bird specimens thought to be Ivory-billed Woodpeckers were discovered to actually be a pair of the even rarer Imperial Woodpecker.

In situations where institutions begin to clear out their collections to make room they run the risk of discarding potentially valuable specimens that could later be identified by more experienced and knowledgeable researchers. Fortunately in the examples above, expert researchers were able to identify the specimens and preserve them for future generations to benefit from.

ADDENDUM: since this posting the following story appeared in Cincinnati.

Photo: female Imperial Woodpecker by Casey Tucker, Wild Auk Photography

Thursday, February 10, 2011

Ontogeny reconfirms Phylogeny

Ontogeny recapitulates phylogeny is a saying put forth by Ernst Haeckel to describe how the process of development in vertebrate embryos mirrors the evolutionary process that vertebrates have undergone through history (e.g. a human embryo goes through stages where they resemble fish, tadpoles, etc.). While Haeckel's original hypothesis is not what exactly happens, it has been shown that closely related organisms undergo similar developmental processes.

A new study out of the Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University may help resolve a long-standing debate on the development of digits in the hands of birds and dinosaurs.
The debate and the findings of the new study are well-reported in an article from ScienceNOW.

Given the plethora of additional evidence supporting a dinosaur origin for birds, hopefully this is the final nail in the coffin for the argument that birds originated from more basal archosaurians.
Photo: Archaeopteryx manus

Tuesday, February 8, 2011

2011--Year that Dinosaurs Returned to Mainstream

2011 is shaping up to be the year of the Dinosaur in the media.

First is the continuation of IDW's "Jurassic Park" comic book series with "Devils in the Desert". The art, which is by comic legend John Byrne, is much better than last year's "Redemption" series. "Devils in the Desert" has received at least one very positive review. IDW is also publishing collections of the original TOPPS Jurassic Park comics from the 1990's.

Additionally, this month Image Comics is publishing a one shot comic titled "Tyrannosaurus Rex."

In January Dark Horse Comics released Ricardo Delgado's "Age of Reptiles" Omnibus, which collects all three "Age of Reptiles" series into one collection.

Later this year FOX broadcasting will be releasing "Terra Nova" from Steve Spielberg. It looks a little like "LOST" meets "Jurassic Park" meets "Avatar". It will be interesting to see how much current dinosaur science is incorporated into this show and how much is left to creative license.

The event that many dinosaur fans are looking forward to is the Discovery Channel's "Reign of the Dinosaurs" which involves many of the great dinosaur artists including Ricardo Delgado and David Krentz.

Later this year, to celebrate the 150th anniversary of the discovery of Archaeopteryx lithographica, Germany is releasing a commemorative Euro coin.
As the above media items are released throughout the year, it will be interesting to see what else is put out there (toys, models, games, books, videos, etc.)

Photo by Casey Tucker--Sauropods escaping from Children's Museum of Indianapolis. Sculpture by Brian Cooley