Study Reveals This Mysterious, Super Long-Necked Triassic Reptile Was a Marine Hunter

The creature’s neck was stiff like a giraffe’s and was nearly three times the length of its torso

Tanystropheus hydroides hunting
An artist's illustration of the Triassic reptile Tanystropheus hydroides hunting with its long neck. Emma Finley-Jacob

New research reveals that a mysterious long-necked reptile from the dawn of the age of the dinosaurs was a marine predator, reports Nicola Davis for the Guardian.

Paleontologists uncovered the creatures’ bones in Germany more than 100 years ago, but until now one of the only things researchers knew for sure about the extinct reptile Tanystropheus was that it had a ridiculously long neck. Specimens ranged in size from roughly four feet to 20 feet long but all had a rigid neck around triple the length of their torso, according to the Guardian.

The divergent sizes and unique physiology of the Tanystropheus specimens that emerged from 242-million-year-old Triassic sediments in Europe sowed debate as to how the fossils should be interpreted, reports Michael Marshall for New Scientist.

“Is it terrestrial or is it marine? Are those juveniles and adults, or are they two different species?” Olivier Rieppel, curator of evolutionary biology at the Field Museum of Natural History and co-author of the new research, tells New Scientist.

In a bid to answer some of these lingering questions, Rieppel and colleagues used computerized tomography to create a 3-D scan of the crushed skull of one of the larger Tanystropheus specimens. This technique allowed the team to reposition each digitized skull fragment and put the skull back together into something closer to its original shape.

Writing in the journal Current Biology, the researchers report that the digitally un-crushed skull revealed nostrils positioned on top of the snout—a trait that facilitates easy breathing in aquatic animals—and pointed, interlocking teeth suited to snagging slippery fish and squid. Speaking with New Scientist, Rieppel adds that “biomechanically, that neck doesn’t make sense on land.”

To figure out if the more diminutive examples of Tanystropheus were just Triassic tykes, the researchers sliced into some of the smaller specimens’ bones. The growth lines inside the bones, which can be used to age animals much like the rings of a tree, suggested the individual was an adult. This finding means there were not one but two species of aquatic, long-necked reptile plying the waters off Pangea, reports Laura Geggel for Live Science.

The researchers dubbed the larger species Tanystropheus hydroides after the serpentine-necked sea monster Hydra of Greek mythology, and the smaller species retains the name Tanystropheus longobardicus, which previously covered all specimens.

Though the animals had similarly long, stiff necks, the creatures were so different in size and dentition that they probably weren’t competing for the same food sources.

"They had evolved to feed on different food sources with different skulls and teeth, but with the same long neck," Stephan Spiekman, a paleontologist at the University of Zurich and lead author of the study, tells Live Science.

In a statement, Spiekman adds, “the small species likely fed on small shelled animals, like shrimp, in contrast to the fish and squid the large species ate. This is really remarkable, because we expected the bizarre neck of Tanystropheus to be specialized for a single task, like the neck of a giraffe. But actually, it allowed for several lifestyles. This completely changes the way we look at this animal.”

The new knowledge gleaned from this research can now be used to classify newly discovered fossils.

“We have found the same genus, Tanystropheus, in China,” Nick Fraser, a paleontologist at National Museums Scotland and co-author of the new research, tells the Guardian. “Our issue there is going to be which species does the Chinese one belong to.”

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