"Long before it's in the papers"
February 01, 2011

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Newfound dinosaur species called “father” of Triceratops

Feb. 1, 2011
Courtesy of Yale University
and World Science staff

Two tank-like rep­tiles, Tri­cer­a­tops and Torosaurus, have long been con­sid­ered the kings of the horned di­no­saurs. But a new dis­cov­ery traces the gi­ants’ family tree fur­ther back in time, sci­en­tists say, when a newly dis­cov­ered spe­cies seems to have reigned long be­fore its better-known de­scen­dants. That would make the beast the ear­li­est known mem­ber of its fam­i­ly, the tri­cer­a­top­sins.

Ti­tanocer­atops ri­valed Tri­cer­a­tops in size, sci­ent­ists say, with an es­ti­mat­ed weight of near­ly 15,000 pounds and a mas­sive eight-foot-long skull. (Cred­it: Nich­o­las Lon­grich/Yale U.)

The new spe­cies, called Ti­ta­no­cer­atops, is said to have ri­valed Tri­cer­a­tops in size, with an es­ti­mat­ed weight of nearly 15,000 pounds and a mas­sive eight-foot-long skull. Its name is a nod to the Greek myth of the Ti­tans, an eld­er race of gods.

Ti­tanocer­atops lived in the Amer­i­can south­west dur­ing the late Cre­ta­ceous pe­ri­od around 74 mil­lion years ago, ac­cord­ing to Yale Uni­vers­ity pa­le­on­tol­ogist Nich­o­las Lon­grich, who is cred­ited with the dis­cov­ery. This sug­gests the family evolved its large size more than five mil­lion years ear­li­er than pre­vi­ously thought, he said. The find­ing, to ap­pear in an up­com­ing is­sue of the jour­nal Cre­ta­ceous Re­search, helps shed light on the poorly un­der­stood ori­gins of these gi­ant horned di­no­saurs, he added.

Lon­grich was search­ing through sci­en­tif­ic pa­pers when he came across a de­scrip­tion of a par­tial ske­l­e­ton of a di­no­saur dis­cov­ered in New Mex­i­co in 1941. The ske­l­e­ton went un­touched un­til 1995, when it was fi­nally pre­pared and iden­ti­fied in­cor­rect­ly, he said, as Pen­tac­er­atops, a spe­cies com­mon to the ar­ea. When the mis­sing part of its frill – the sig­na­ture fea­ture of the horned di­no­saurs – was re­con­struct­ed for dis­play in the Ok­la­ho­ma Mu­se­um of Nat­u­ral His­to­ry, it was mod­eled af­ter Pen­ta­cer­atops.

Il­lus­tra­tion of Ti­ta­no­cer­atops, thought to be the an­ces­tor of the better-known Tri­cer­a­tops. (Cred­it: Nich­o­las Lon­grich/Yale U.)

“When I looked at the ske­l­e­ton more close­ly, I real­ized it was just too dif­fer­ent from the oth­er known Pen­ta­cer­atops to be a mem­ber of the spe­cies,” Lon­grich said, adding that the spec­i­men’s size in­di­cat­ed that it likely weighed about twice as much as adult Pen­ta­cer­atops. The new spe­cies is very si­m­i­lar to Tri­cer­a­tops, but with a thin­ner frill, long­er nose and slightly big­ger horns, Lon­grich said.

In­stead, Lon­grich be­lieves that Ti­tano­cer­atops is the an­ces­tor of both Tri­cer­a­tops and Toro­saurus, and that the lat­ter two split sev­er­al mil­lion years af­ter Ti­tano­cer­atops evolved. “This ske­l­e­ton is ex­actly what you would ex­pect their an­ces­tor to look like,” he said.

Ti­tanocer­atops was probably only around for about a mil­lion years, ac­cord­ing to Lon­grich, while the tricer­atop­sian family ex­isted for a to­tal of about 10 mil­lion years and roamed be­yond the Amer­i­can south­west in­to oth­er parts of the coun­try and as far north as Can­a­da.

To con­firm the dis­cov­ery be­yond any doubt, Lon­grich hopes pa­le­on­tol­ogists will find oth­er fos­sil skel­e­tons that in­clude in­tact frills, which would help con­firm the dif­fer­ences be­tween Ti­tano­cer­atops and Pen­ta­cer­atops. “There have got to be more of them out there,” Lon­grich said.

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Two tank-like reptiles, Triceratops and Torosaurus, have long been considered the kings of the horned dinosaurs. But a new discovery traces the giants’ family tree further back in time, scientists say, when a newly discovered species seems to have reigned long before its better-known descendants. That would make the beast the earliest known member of its family, the triceratopsins. The new species, called Titanoceratops, is said to have rivaled Triceratops in size, with an estimated weight of nearly 15,000 pounds and a massive eight-foot-long skull. Its name is a nod to the Greek myth of the Titans, an elder race of gods. Titanoceratops lived in the American southwest during the late Cretaceous period around 74 million years ago, according to Yale University paleontologist Nicholas Longrich, who is credited with the discovery. This suggests the group evolved its large size more than five million years earlier than previously thought, he said. The finding, to appear in an upcoming issue of the journal Cretaceous Research, helps shed light on the poorly understood origins of these giant horned dinosaurs, he added. Longrich was searching through scientific papers when he came across a description of a partial skeleton of a dinosaur discovered in New Mexico in 1941. The skeleton went untouched until 1995, when it was finally prepared and identified incorrectly, he said, as Pentaceratops, a species common to the area. When the missing part of its frill – the signature feature of the horned dinosaurs – was reconstructed for display in the Oklahoma Museum of Natural History, it was modeled after Pentaceratops. “When I looked at the skeleton more closely, I realized it was just too different from the other known Pentaceratops to be a member of the species,” Longrich said, adding that the specimen’s size indicated that it likely weighed about twice as much as adult Pentaceratops. The new species is very similar to Triceratops, but with a thinner frill, longer nose and slightly bigger horns, Longrich said. Instead, Longrich believes that Titanoceratops is the ancestor of both Triceratops and Torosaurus, and that the latter two split several millions years after Titanoceratops evolved. “This skeleton is exactly what you would expect their ancestor to look like,” he said. Titanoceratops was probably only around for about a million years, according to Longrich, while the triceratopsian family existed for a total of about 10 million years and roamed beyond the American southwest into other parts of the country and as far north as Canada. To confirm the discovery beyond any doubt, Longrich hopes paleontologists will find other fossil skeletons that include intact frills, which would help confirm the differences between Titanoceratops and Pentaceratops. “There have got to be more of them out there,” Longrich said.