Mystery of how a 242 million-year-old reptile with a neck three times the length of its torso was able to move around is finally solved after 3D skull reconstruction reveals it lived in the ocean
- Bizarre animal with 10-foot-long giraffe-style neck was a paleontological oddity
- New evidence shows it lived underwater and may have moved to land to lay eggs
- Tanystropheus also evolved into two different species, one larger than the other
A 242 million-year-old reptile with a neck three times the length of its torso lived in the ocean, a 3D skull reconstruction reveals.
Scientists describe the weird 20-foot-long creature and its incredible giraffe-like neck as a ‘paleontological absurdity’.
Fossils of the creature, belonging to the Tanystropheus genus, were discovered back in 1852 and have been puzzling scientists ever since.
Experts couldn’t tell how the creature would have been able to support its ludicrously long neck if it had been roaming on land during the middle Triassic period.
But a new study led by the University of Zurich in Switzerland has now shown that the creature lived in water and was ‘surprisingly adaptable’.
Nostrils located on the top of the snout and curved teeth were perfectly adapted for catching slippery prey such as fish and squid.
The Tanystropheus genus also evolved into two different species, one larger than the other, the new research concludes.
The neck of Tanystropheus was three times as long as its torso, but had only thirteen extremely elongated vertebrae
‘I’ve been studying Tanystropheus for over thirty years, so it’s extremely satisfying to see these creatures demystified,’ said study author Olivier Rieppel, a paleontologist at the Field Museum in Chicago.
‘Tanystropheus looked like a stubby crocodile with a very, very long neck.
‘That neck doesn’t make sense in a terrestrial environment – it’s just an awkward structure to carry around.
‘To clarify its taxonomy is an important first step to understanding that group and its evolution.’
242 million years ago, when dinosaurs were just starting to emerge on land, the sea was ruled by giant reptiles.
The digitially reconstructed skull of Tanystropheus, using CT scans of the crushed skull pieces
Reconstructions of the skeletons of Tanystropheus hydroides (large species, newly named) and Tanystropheus longobardicus (small species). The outline of a 5.5-foot-tall diver serves as the scale
Tanystropheus, which measured about 20 feet long, had a 10-foot neck and a torso around a third of that size – about 3.3 feet, with the remaining length made up by its tail.
At one point, paleontologists thought Tanystropheus was a flying pterosaur, like a pterodactyl, and that its long, hollow bones were phalanges in the finger that supported the wing, before working out that those were elongated neck bones.
In the same region where many of the Tanystropheus fossils were found in modern-day Switzerland, there were also fossils from similar-looking animals that were only about four feet long.
Scientists were unsure if these were land-dwellers or marine animals, whether the smaller specimens were juveniles, or if they were a separate species.
Oddly for animals with such long necks, they only had 13 highly elongated neck vertebrae.
Again, Tanystropheus are a bit like giraffes in this sense, which have only seven neck bones, just like humans.
And Tanystropheus necks were rather inflexible, reinforced with extra bones called cervical ribs.
Nostrils located on the top of the snout and curved teeth, perfectly adapted for catching slippery prey
Scientists still weren’t sure if it lived on land or in the water, and they didn’t know if smaller specimens were juveniles or a completely different species.
The large Tanystropheus fossils’ skulls had been crushed, but researchers took computed tomography (CT) scans of the fossil slabs and generated 3D images of the bone fragments inside.
WHAT IS A CT SCAN?
CT (Computerised tomography) scan uses X-rays and a computer to create detailed images.
They are several single X-rays that create a 2-dimensional images of a ‘slice’ or section of the specimen/individual.
Although an X-ray creates a flat image, several can be combined to construct complex 3D images.
A CT scanner emits a series of narrow beams as it moves through an arc.
This is different from an X-ray machine, which sends just one radiation beam.
The CT scan produces a more detailed final picture than an X-ray image.
This data is transmitted to a computer, which builds up a 3-D cross-sectional picture of the part of the body and displays it on the screen.
The skull was reconstructed in unprecedented detail using synchrotron radiation micro-computed tomography (SRμCT) – an extremely powerful form of CT scanning.
‘The power of CT scanning allows us to see details that are otherwise impossible to observe in fossils,’ said study lead author Stephan Spiekman at the University of Zurich.
‘From a strongly crushed skull we have been able to reconstruct an almost complete 3D skull, revealing crucial morphological details.’
By digitally reassembling the scans them, researchers found evidence that the animals were water-dwelling.
The skulls had key features, including nostrils on top of the snout like a crocodile’s, suggesting Tanystropheus lived in the water.
The slender beast probably lay in wait, waiting for fish and squid-like animals to swim by, and then snagged them with its long, curved teeth.
Researchers suggest that Tanystropheus may have come to land to lay eggs but mostly stayed in the ocean.
To learn whether the small specimens were juveniles or a separate species, the researchers examined the bones for signs of growth and ageing.
Growth rings in bones helped them determine that the big and little Tanystropheus were separate species that could live alongside each other without competing because they hunted different prey.
The different sizes, along with cone-shaped teeth in the big species and crown-shaped teeth in the little species, meant they probably weren’t competing for the same types of food.
‘These two closely related species had evolved to use different food sources in the same environment,’ said Spiekman.
‘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 specialised 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 researchers named the larger one Tanystropheus hydroides, after the long-necked hydras in Greek mythology, while the smaller one bears the original name, Tanystropheus longobardicus, used by researchers in previous studies.
‘For many years now we have had our suspicions that there were two species of Tanystropheus, but until we were able to CT scan the larger specimens we had no definitive evidence. Now we do,’ said study co-author Nick Fraser at National Museums Scotland.
WHAT WERE THE TANYSTROPHEIDS?
Tanystropheids were likely mainly based in aquatic environments but studies show they could walk on land
Tanystropheid (genus Tanystropheus) was a long-necked reptile that lived during the Triassic period – between 252 million and 201 million years ago.
It measured around 20 feet long, with an extremely elongated neck of about 9.8 feet – longer than its body and tail combined.
The neck was composed of 12–13 extra-long cervical vertebrae.
Fossils of this creature have been found in Europe and the Middle East.
Its habitat was likely aquatic – most fossils studied from the tanystropheid group belonged to marine environments – and fed on fish.
However, Tanystropheus would also have been capable of walking around on land, studies have said.
The teeth at the front of the narrow snout were long and conical for gripping slippery prey such as fish or squid from the waters.
Source: Read Full Article