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Goodbye Triceratops, hello Torosaurus
07 August 2010
Another cherished childhood myth demolished. This week paleontologists Jack Horner (one of those I respect the most) and John Scannella revealed that the beloved Triceratops was not a separate species, but rather the immature form of Torosaurus. First Brontosaurus, now Triceratops disappears.
Well, okay, it doesn't vanish. It may simply get a name change, like Brontosaurus became Apatosaurus. In part it's because paleontologists are learning more almost daily and the fossil records are at best spotty and it often takes years or decades to assemble evidence that clearly identifies adults and juveniles.
Fossils of both were discovered by the famed collector Othniel Marsh who raced against his competitor, Edward Drinker Cope, in the late 1800s to discover the most dinosaur species. Marsh naturally considered them to be separate species, but then he didn't have the later finds to create a broader picture of their development.
Unfortunately, a lot of media reports have said Triceratops "never existed." Even the reputable Globe and Mail persisted in this folly, in its Saturday edition. No, silly clueless reporters, that's not what it means at all. Simply because I thought a dog was a Border Collie and turned out to be a Sheltie doesn't mean it never existed. It's merely a name change, a recognition of a previous mistake in identification. It may not be a separate species but it's still acceptable to refer to a Triceratops, but with the caveat that you are referring to a younger version or Torosaurus.*
Or it's very possible that Torosaurus will vanish and the name Triceratops will be used for the adult version as well. After all, Triceratops has had a starring role in popular imagination ever since Edgar Rice Burroughs wrote The Land That Time Forgot.
According to Tech Journal:
This was all reported in detail in the Journal of Vertebrate Paleontology (vol 30, p 1157). I assume you all read it? Okay, then you probably read the report in the New Scientist.
This is not the sole report of one dinosaur being identified as a separate species when later evidence suggests it was a younger version of another. In 2009, Horner and fellow paleontologist Mark Goodwin suggested Dracorex and Stygimoloch were juveniles forms of the thick-headed (almost politician-like) Pachycephalosaurus . And the small Nanotyrannus was deemed a juvenile form of Tyrannosaurus Rex.
Despite the impression films like Jurassic Park have given, paleontology is still a young science. A lot of old notions have changed as new discoveries are made, and as more reseach is done. And there is still a lot to learn. A name change is really a minor thing and even if the name Triceratops disappears, it neither means the animal never existed nor that scientists were wrong about its existence. They simply didn't recognize that what they now realize was the baby ceratopsian was on its way to become a bigger, meaner Torosaur.
~~~~~
* I have to consult my style manual, but I believe that, because they are formal, scientific names for species, that these names deserve a capital first letter, not, as often seen, a lowercase letter.
Fossils of both were discovered by the famed collector Othniel Marsh who raced against his competitor, Edward Drinker Cope, in the late 1800s to discover the most dinosaur species. Marsh naturally considered them to be separate species, but then he didn't have the later finds to create a broader picture of their development.
Unfortunately, a lot of media reports have said Triceratops "never existed." Even the reputable Globe and Mail persisted in this folly, in its Saturday edition. No, silly clueless reporters, that's not what it means at all. Simply because I thought a dog was a Border Collie and turned out to be a Sheltie doesn't mean it never existed. It's merely a name change, a recognition of a previous mistake in identification. It may not be a separate species but it's still acceptable to refer to a Triceratops, but with the caveat that you are referring to a younger version or Torosaurus.*
Or it's very possible that Torosaurus will vanish and the name Triceratops will be used for the adult version as well. After all, Triceratops has had a starring role in popular imagination ever since Edgar Rice Burroughs wrote The Land That Time Forgot.
According to Tech Journal:
Quote
This discovery comes from a study of the iconic dinosaur Triceratops and its close relative Torosaurus. Their skulls are markedly different but are actually from the very same species, argue John Scannella and Jack Horner at the Museum of the Rockies in Bozeman, Montana.
Triceratops had three facial horns and a short, thick neck-frill with a saw-toothed edge. Torosaurus also had three horns, though at different angles, and a much longer, thinner, smooth-edged frill with two large holes in it. So it's not surprising that Othniel Marsh, who discovered both in the late 1800s, considered them to be separate species.
Now Scannella and Horner say that triceratops is merely the juvenile form of torosaurus. As the animal aged, its horns changed shape and orientation and its frill became longer, thinner and less jagged. Finally it became fenestrated, producing the classic torosaurus form (see diagram, right).
This extreme shape-shifting was possible because the bone tissue in the frill and horns stayed immature, spongy and riddled with blood vessels, never fully hardening into solid bone as happens in most animals during early adulthood. The only modern animal known to do anything similar is the cassowary, descended from the dinosaurs, which develops a large spongy crest when its skull is about 80 per cent fully grown.
Triceratops had three facial horns and a short, thick neck-frill with a saw-toothed edge. Torosaurus also had three horns, though at different angles, and a much longer, thinner, smooth-edged frill with two large holes in it. So it's not surprising that Othniel Marsh, who discovered both in the late 1800s, considered them to be separate species.
Now Scannella and Horner say that triceratops is merely the juvenile form of torosaurus. As the animal aged, its horns changed shape and orientation and its frill became longer, thinner and less jagged. Finally it became fenestrated, producing the classic torosaurus form (see diagram, right).
This extreme shape-shifting was possible because the bone tissue in the frill and horns stayed immature, spongy and riddled with blood vessels, never fully hardening into solid bone as happens in most animals during early adulthood. The only modern animal known to do anything similar is the cassowary, descended from the dinosaurs, which develops a large spongy crest when its skull is about 80 per cent fully grown.
This was all reported in detail in the Journal of Vertebrate Paleontology (vol 30, p 1157). I assume you all read it? Okay, then you probably read the report in the New Scientist.
This is not the sole report of one dinosaur being identified as a separate species when later evidence suggests it was a younger version of another. In 2009, Horner and fellow paleontologist Mark Goodwin suggested Dracorex and Stygimoloch were juveniles forms of the thick-headed (almost politician-like) Pachycephalosaurus . And the small Nanotyrannus was deemed a juvenile form of Tyrannosaurus Rex.
Despite the impression films like Jurassic Park have given, paleontology is still a young science. A lot of old notions have changed as new discoveries are made, and as more reseach is done. And there is still a lot to learn. A name change is really a minor thing and even if the name Triceratops disappears, it neither means the animal never existed nor that scientists were wrong about its existence. They simply didn't recognize that what they now realize was the baby ceratopsian was on its way to become a bigger, meaner Torosaur.
~~~~~
* I have to consult my style manual, but I believe that, because they are formal, scientific names for species, that these names deserve a capital first letter, not, as often seen, a lowercase letter.
