Pterosaurs did not skim water surface for food, reveals study

British palaeontologists from the Universities of Sheffield, Portsmouth and Reading, have in a joint research, found that the extinct pterosaurs did not gather their food by skimming the water surface like modern day Rynchops.

Washington, July 24 : British palaeontologists from the Universities of Sheffield, Portsmouth and Reading, have in a joint research, found that the extinct pterosaurs did not gather their food by 'skimming' the water surface like modern day Rynchops.

Previous studies had suggested that pterosaurs might have fed like modern-day 'skimmers', a rare group of shorebirds, belonging to the Rynchops group. These sea-birds fly along the surface of lakes and estuaries scooping up small fish and crustaceans with their submerged lower jaw.

Inferred structural similarities between pterosaur and Rynchops jaws had been used to suggest that some pterosaur were anatomically suited for skimming.

Using new physical and mathematical modelling, the team, however, proved that the thicker jaws of pterosaurs would have made it difficult for them to deflect water the way the extraordinarily slim bills of Rynchops do.

By combining experiments using life-size models of pterosaur and skimmer jaws with hydrodynamic and aerodynamic modelling, the scientists demonstrated that skimming required more energy than the giant reptilian fliers were likely able to supply.

According to the scientists, the pterosaurs, weighing more than one kilogram, would not have been able to skim at all.

Further anatomical comparisons between the highly-specialised skull of Rynchops and those of postulated skimming pterosaurs revealed that even smaller forms were poorly adapted for skim-feeding.

The researchers believe the pterosaurs would have in fact fed using more conventional methods.

The research is published in this month's issue of PLoS Biology. The researchers involved in the project are: Dr Stuart Humphries, University of Sheffield; Dr Richard Bonser, University of Reading; Mark Witton, University of Portsmouth and Dr David Martill, University of Portsmouth.

ANI