Caption: Artistic interpretation of a Tanystropheus hydroides being decapitated. Credit: Roc Olivé (Institut Català de Paleontologia Miquel Crusafont)/FECYT
New fossil findings have brought to light a vulnerability in the long-necked marine reptiles known as Tanystropheus. Researchers have discovered bite marks on the necks of these ancient creatures, providing the first direct evidence of their susceptibility to predators. Despite their successful survival spanning 175 million years, their elongated necks turned out to be an evolutionary disadvantage.
During the dinosaur era, many marine reptiles exhibited remarkably long necks compared to their modern reptilian counterparts. Although this physical feature seemed to serve them well in evolutionary terms, paleontologists have long suspected that it also made them easy targets for predators. Now, after almost two centuries of ongoing research, fossil evidence has confirmed this hypothesis in a rather graphic manner.
Published in the journal Current Biology on June 19, a study focused on two Triassic species of Tanystropheus, reptiles distantly related to crocodiles, birds, and dinosaurs, known for their peculiar necks. These marine reptiles possessed necks comprised of 13 extremely elongated vertebrae and rigid, strut-like ribs. Consequently, they likely had inflexible necks and relied on ambush tactics to catch their prey. However, it appears that predators took advantage of this distinctive neck structure for their own benefit.
Careful examination of fossilized bones has revealed clear bite marks on the necks of two well-preserved specimens from different Tanystropheus species. In one instance, the bite marks coincide with the area where the neck was severed. These findings provide rare and gruesome evidence of predator-prey interactions dating back over 240 million years, according to the researchers.
“Paleontologists have long speculated that these long necks constituted an obvious weak spot for predation, as vividly depicted almost 200 years ago in a famous painting by Henry de la Beche from 1830,” explained Stephan Spiekman from the Staatliches Museum für Naturkunde Stuttgart, Germany. “However, until our current study on these two Tanystropheus specimens, there was no evidence of decapitation or any other form of neck-targeted attack found in the abundant fossil records of long-necked marine reptiles.”
Spiekman, who conducted the study as part of his doctoral work at the Paleontological Museum of the University of Zurich, Switzerland, noted that two Tanystropheus species coexisted in the same environment. One species, measuring about a meter and a half in length, likely fed on soft-shelled animals like shrimp, while the much larger species, reaching up to six meters in length, preyed on fish and squid. The shape of their skulls provides clear evidence that Tanystropheus spent most of its time in water.
The presence of two specimens with well-preserved heads and abruptly terminated necks had long raised speculation that their necks had been bitten off. However, no detailed study had been conducted on this matter. For this new investigation, Spiekman collaborated with Eudald Mujal, also from the Stuttgart Museum and a research associate at the Institut Català de Paleontologia Miquel Crusafont, Spain. Mujal specializes in fossil preservation and the study of predatory interactions through bite traces on bones. After examining the two specimens in Zurich, they concluded that the necks had indeed been severed by another animal.
“One intriguing observation is that the skulls and necks are undisturbed, showing only slight disarticulation resulting from the natural
Frequently Asked Questions (FAQs) about long-necked reptiles
What does the fossil evidence reveal about the vulnerability of long-necked marine reptiles?
The fossil evidence confirms that long-necked marine reptiles, specifically Tanystropheus, were vulnerable to predators. Bite marks found on their necks provide direct proof of this vulnerability, despite their successful survival over a span of 175 million years.
How did the long necks of Tanystropheus make them susceptible to predators?
The elongated necks of Tanystropheus provided a potential weak spot for predation. The unique neck structure, composed of elongated vertebrae and rigid ribs, allowed predators to take advantage of it, leading to decapitation and evident bite marks on the necks of the fossilized specimens.
How long have marine reptiles with long necks existed?
Marine reptiles with long necks, including Tanystropheus, thrived for approximately 175 million years. Their elongated necks were considered a successful evolutionary strategy, found in various marine reptiles throughout this extensive time span.
What does this discovery reveal about the trade-offs in evolution?
The discovery highlights the concept of trade-offs in evolution. Despite the vulnerability posed by their long necks, the advantage of having an elongated neck seemed to outweigh the risk of predation, as evidenced by the prolonged survival and success of Tanystropheus and other long-necked marine reptiles.
