Scientists digitally reconstruct skull of mysterious Triassic reptile

As the scientists note, its "paleobiology remains contentious," some scientists believe it lived on land other stated that it was an aquatic-dwelling reptile.

Tanystropheus (photo credit: Wikimedia Commons)
(photo credit: Wikimedia Commons)
Scientists have virtually reconstructed the skull of Tanystropheus, an iconic reptile from the Triassic period with a long disputed past, shedding new light on the mysterious reptile and revealing its morphology for the first time.
The reptile itself has long been purported to have a long stiffened neck with short crocodile-like body, resembling one of the heads of the Hydra from Greek mythology.
As the scientists note, its "paleobiology remains contentious." Some scientists believe it lived on land other stated that it was an aquatic-dwelling reptile.
Findings from the new research, published in Current Biology, have placed the reptile in the water - considering the skull is specialized for hunting in the water, indicated by the placement of the nostrils on the top of the snout, a "fish-trap-type dentition." Additionally, the organism sports six long, curved fangs, with the anterior three being the largest and interlocked - sharing the characteristics of a marine predator.
The scientists digitally re-pieced the skull together using high-resolution synchrotron radiation microtomography (SRμCT), pulling together a nearly complete reconstruction of the skull - originally found in Monte San Giorgio on the border of Switzerland.
"The fossilized skull... is heavily compressed, obscuring much of its anatomy (Figure 1A). However, the compression caused individual bones to disarticulate rather than deform, so they largely maintain their three-dimensional morphology," the study authors stated in the newly published research.
The scientists were also able to distinguish that there were two different species of Tanystropheus - one small, one large. It was once believed that these skeletons were just the adult and juvenile versions of the reptile, however, new revelations have proven that these in fact are two different species.
"The SRμCT data and limb bone paleohistology reveal that the large morphotype represents a separate species (Tanystropheus hydroides sp. nov.)," the study authors stated.
"Skeletochronology of the small morphotype specimens indicates that they are skeletally mature despite their small size, thus representing adult individuals of Tanystropheus longobardicus," the authors explained. "The co-occurrence of these two species of disparate size ranges and dentitions provides strong evidence for niche partitioning, highlighting the surprising versatility of the Tanystropheus bauplan and the complexity of Middle Triassic nearshore ecosystems."
"Food resources in an ecosystem are limited, and animals that look similar often develop different strategies ... It's called niche partitioning," co-author Torsten Scheyer told CNN. "So, they shared the same habitat, but didn't get in each others' way too much."
As it has proven and stated in the study, the reconstruction of the skull is invaluable in shedding light on the morphology and paleobiology of this long extinct organism.
"The bizarre Tanystropheus represents a particularly interesting case study in this regard due to its unique morphology among tetrapods, exemplified by its extremely long neck consisting of only 13 very elongate vertebrae," the authors note. "The skull reconstruction based on PIMUZ T 2790 deviates strongly from that of other early archosauromorphs and reveals that T. hydroides hunted in an aquatic environment, using its long fang-like teeth and a lateral snapping bite to seize its prey.
"Tanystropheus hydroides and T. longobardicus were two closely related species that almost certainly co-occurred in the same habitat," they concluded. "This remarkable case of niche partitioning highlights the versatility of the Tanystropheus bauplan and the complexity of Middle Triassic marine trophic networks within 10 million years after the End-Permian extinction event, and the major role of reptiles therein."