Jurᴀssic Ichthyosaurs divided food resources to co-exist

Scientists from the University of Bristol discovered that early Jurᴀssic ichthyosaur juveniles have predatory specializations.

Their findings, which were published in the Journal of Anatomy, suggest that physical differences in their snouts indicate that they evolved to have different diets and were not competing for the same resource.

Jurᴀssic ichthyosaurs divided food resources to co-existThe skull of Ichthyosaurs Hauffiopteryx typicus from the Strawberry Bank Lagerstätt, one of the specimens that were the subject of this study. Credit: Bath Royal Literary and Scientific Insтιтution Collections

The classic’sea dragons,’ ichthyosaurs, were dolphin-shaped marine predators that fed on fish and squid-like swimming shellfish.

The Lower Jurᴀssic ichthyosaurs are renowned since the first specimens were discovered over 200 years ago at Lyme Regis in southern England by the great fossil collector and palaeontologist Mary Anning. Her specimens have long, slender snouts on some, and short, broad snouts on others.

“Functional studies need excellent three-dimensional specimens,” said Matt Williams of the Bath Royal Literary and Scientific Insтιтution, “and the Lower Jurᴀssic ichthyosaur fossils from Strawberry Bank in Ilminster are just that. Mary Anning’s fossils are amazing, but they are mostly squashed flat.”

“Our idea was to CT scan the specimens,” said Dr Ben Moon, of Bristol’s School of Earth Sciences and a supervisor of the study. “The scans allow us to make a detailed, 3D model of the skull in the computer, and it can then be tested for the likely forces experienced during biting.”

“After we had the models, we could stress test them,” supervisor Andre Rowe said. “We tested and confirmed the hypothesis that the slender-snouted ichthyosaur had a quick but weak bite, and the broad-snouted ichthyosaur had a slow but powerful bite.”

“Confirming the supposition was important,” author Professor Michael Benton remarked. “It’s important we apply rigorous scientific approaches such as these engineering analyses. The two species of ichthyosaur presumably chased fast-moving prey (the fast biter) and slower, tough-shelled prey (the slow, powerful biter).

Jurᴀssic ichthyosaurs divided food resources to co-existFigure showing 3D models of Ichthyosaurs skull. Credit: Prof Mike Benton

“I learned about CT scanning, model construction, and biomechanical testing using standard engineering software that is used to test how buildings and large structures bend,” said Sarah Jamison-Todd, who completed the work as part of her MSc in Palaeobiology.

Prof Benton concluded: “Modern predators like sharks and killer whales tend to eat anything they can, so it is exciting to be able to show that in the Jurᴀssic there were definite specializations. The work can be extended to explore other marine reptiles such as plesiosaurs and crocodiles, so we get a detailed picture of these amazing and alien worlds of the Jurᴀssic oceans.”

Provided by University of Bristol

More information: Sarah Jamison‐Todd et al, (2022). Dietary niche parтιтioning in Early Jurᴀssic ichthyosaurs from Strawberry Bank, Journal of Anatomy. DOI: 10.1111/joa.13744

Related Posts

Forgotten Indigenous child slaves of New France revealed in new studies

Forgotten Indigenous child slaves of New France revealed in new studies

Historical accounts between 1632 and 1760 show a chilling reality: 734 Indigenous children were enslaved in France’s North American colony. These children, torn from their families and…

Exceptionally preserved Roman wicker well with ladder unearthed in Norfolk

Exceptionally preserved Roman wicker well with ladder unearthed in Norfolk

Archaeologists at Oxford Archaeology have uncovered an astonishingly well-preserved Roman-era well in Norfolk, England, that offers rare insight into the lives of people in Roman Britain some…

Ancient Egyptian genome reveals 4,500-year-old genetic ties to Mesopotamia

Ancient Egyptian genome reveals 4,500-year-old genetic ties to Mesopotamia

For the first time, scientists have successfully sequenced the complete genome of an individual from ancient Egypt, offering unprecedented insights into early Egyptian ancestry and revealing a…

Neanderthals operated prehistoric “fat factory” 125,000 years ago on German lakeshore

Neanderthals operated prehistoric “fat factory” 125,000 years ago on German lakeshore

Neanderthals in central Germany 125,000 years ago employed an advanced method of food preparation, according to a recent study: systematically stripping fat from the bones of large…

Exceptionally large Roman shoes discovered at Magna fort near Hadrian’s Wall

Exceptionally large Roman shoes discovered at Magna fort near Hadrian’s Wall

Archaeologists excavating at Magna, or Carvoran, a Roman fort near Hadrian’s Wall in Northumberland, England, have uncovered an amazing treasure trove of ancient leather shoes—many of them…

Hymn to Babylon discovered, revealing ancient Mesopotamian city life

Hymn to Babylon discovered, revealing ancient Mesopotamian city life

In a collaboration between Ludwig Maximilian University of Munich (LMU) and the University of Baghdad, an ancient Babylonian hymn dating back over two millennia has been rediscovered…