I am a PhD student at the Museum of the Rockies & the Department of Earth Sciences at Montana Sate University in Bozeman, Montana. My research focuses on Triceratops - the famous three horned dinosaur. I'm interested in how Triceratops lived,
what its world was like, and what forces shaped its evolutionary
history. It's important that we have a good idea of what has occurred
in the past so that we can better understand what is happening right
now, especially since we have the ability to affect biodiversity in ways
that no single species has before. We can push countless species that
are standing on the brink of extinction and lose them forever, or become
better stewards of this planet and the creatures that inhabit it. I
think Triceratops has a lot to say about how things might turn out, where things might go wrong, and what we should keep in mind.
8/28/2012: A few months ago, Nicholas Longrich and Daniel Field of Yale University published a paper entitled 'Torosaurus is not Triceratops: Ontogeny in Chasmosaurine Ceratopsids as a Case Study in Dinosaur Taxonomy' in PLoS ONE. This paper is freely available here.
12/14/2011: Today, a paper by Jack Horner and I on the controversial dinosaur 'Nedoceratops hatcheri' was published in PLoS ONE.
Earlier this year, Andrew Farke presented evidence that 'Nedoceratops' is distinct from Triceratops. His paper is freely available here. Our new paper (freely available here) presents evidence that suggests 'Nedoceratops' actually represents a transitional growth stage of Triceratops.
The skull of 'Nedoceratops' at the Smithsonian. Photo taken by J. Scannella, provided courtesy of USNM.
Immature Triceratops have a short, solid frill at the back of their skull. We've recently learned that as Triceratops matured, the frill expanded and became much thinner until it eventually formed large holes in the parietal (the central bone of the frill). For many years, specimens with holes in their parietal had been assigned to a different species of dinosaur ('Torosaurus latus'). But now it seems that rather than being a different dinosaur, 'Torosaurus' is actually the mature form of Triceratops.
The cool thing is that when we examine the frill of Triceratops under a microscope, we can actually see how it was changing shape. We can see how it was growing, we can see how it was expanding, and we can actually see the holes forming in Triceratops with solid frills. We can also see that very large specimens of Triceratops, previously thought to be 'old adults', were still in the process of changing shape when they died.
So, where does 'Nedoceratops' fit in? 'Nedo' has always been interesting because, unlike typical Triceratops, it has a small hole in the same place where in 'Torosaurus' there are big holes. Jack and I propose that 'Nedoceratops' represents a transitional specimen, a dinosaur that was caught in the act of developing holes in its parietal. Had it not died when it did, it likely would have continued to develop into what has been known as 'Torosaurus.' So, 'Nedoceratops' and 'Torosaurus' actually represent growth stages of Triceratops (Triceratops was named first, so that's the name that survives).
We are still learning a tremendous amount about Triceratops - and there are more discoveries to be announced in the near future . . .
How Raptors Kill
For several years, I have been involved in a study with Denver Fowler, Liz Freedman, and Robert Kambic on how Deinonychus and other 'raptors' (both living and extinct) use their claws to kill. The first part of this study (focusing on living birds of prey) was published in 2009 and is freely available here.
Today, the second part of this study was published in PLoS ONE and is freely available here. Part II applies what we've learned about living raptors to Deinonychus, Velociraptor, and other small theropod dinosaurs. It paints a pretty frightening picture of the predatory habits of these animals. We've named the model for their predatory behavior the 'Raptor Prey Restraint' (RPR or 'Ripper') Model. If you can image what it might be like to be attacked and eaten by a human-sized flightless hawk, you can see why it's probably a good thing that you don't have to worry about Deinonychus whenever you go out for a walk . . .
An illustration of the RPR predatory behavior model. Artwork by Nathan Carroll (from Fowler et al., 2011).
Turns out, the same features which made these dinosaurs such efficient killers may have also contributed to the origin of flapping and flight in birds. Denver Fowler discusses this more here.
12/14/2011: The new Museum of the Rockies paleohistology website is up and running. Visit it at www.morhistologylab.org
12/7/2011: Jack Horner's recent TED talk on Shape Shifting Dinosaur Skulls:
12/2/2011: This summer, Ziya Tong dropped by the Museum of the Rockies with a few questions about the growth and development of Triceratops. See the Daily Planet segment here.
1/21/2011: My fellow ceratopsid worker, Andrew Farke, has published
a study on the enigmatic Nedoceratops hatcheri. This paper is freely available online. In
our 2010 paper, Jack Horner and I presented evidence which suggests that Nedoceratops
is actually Triceratops - an idea that's been around since the 1930's.
Andy disagrees and outlines his reasons in the new paper. 'Debates' like this
one are part of the scientific process. Hypotheses are scrutinized and tested
multiple times. There will be more news on the 'Nedoceratops'-debate in
the coming months.
1/12/2011: I had the opportunity to give a short lecture on Triceratops
and 'Torosaurus' for Club320 at the Museum of
the Rockies 'Coronas with Jack' event. There were some great questions
afterwards. Many people would like to know how to tell a male Triceratops
from a female. I'll get back to you . . .
ontogeny with Club320.
Jack Horner and I
published a paper in the summer of 2010 which suggests that 'Torosaurus' and Triceratops
were actually the same dinosaur. We found evidence that as Triceratops
grew up, its skull underwent a series of transformations resulting in the
morphology that has previously been referred to as 'Torosaurus latus.'
In other words, 'Torosaurus' is actually just a full grown Triceratops.
Because Triceratops was named first - that's the name that sticks. I
know some people were upset and thought that we were losing Triceratops
- but not to worry, Triceratops is here to stay. 'Torosaurus' though
. . .
This research was
reported on by a number of sources, including:
And if you're still worried about Triceratops, you can always join the 'Save the Triceratops'
Lee Hall (in white) and I pull a Triceratops from the Hell Creek Formation.
e-mail: jscannella (at) gmail dot com
Copyright John Scannella
JohnScannella.com: Where Triceratops Lives.
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