Nav: Home

Crocodiles and dolphins evolved similar skulls to catch the same prey: Study finds

March 07, 2017

A new study involving biologists from Monash University Australia has found that despite their very different ancestors, dolphins and crocodiles evolved similarly-shaped skulls to feed on similar prey.

Dolphins and crocodiles now live in rivers and oceans, but each evolved from land-based animals. Feeding in water has many new challenges. This new study shows that despite being separated by 300 million years, dolphins and crocodiles found comparable solutions to these problems, and evolved skull shapes that are remarkably similar.

"Our results suggest the remarkable similarity between some crocodilians and toothed whales is driven by what they eat rather than where they live," said lead author Mr Matthew McCurry from the Monash School of Biological Sciences.

Previously no rigorous attempt had been made to show how similar the head shapes of dolphins and crocodiles really are. It had been thought that aspects such shallow seas or rivers contributed to the similarity of the skulls of crocodilians (crocodiles and alligators) and toothed whales (dolphins, orca and relatives). But a study published in Proceedings of the Royal Society B: Biological Sciences has debunked this long-held view.

Having a long, thin snout must have great advantages when trying to catch small fish, both for crocodilians and toothed whales.

"What is really important about this study is that it will help us predict the diet of extinct aquatic mammals and reptiles just from the shape of their skulls," said Mr McCurry.

The authors used medical CT and laser 3D scanning to digitally capture the skulls of museum specimens from around the world. Once digitised, the authors could examine the shape of the skulls in detail without having them in one location. Using sophisticated mathematical techniques to analyse 3D shape, the researchers could show how diet, habitat and prey size correlated with skull shape.

"Crocodiles and dolphins seem so different to us, but our study shows that many of them are in fact remarkably similar, and this is really down to how they catch their food," said study co-author Associate Professor Alistair Evans, also from the Monash School of Biological Sciences.

Future research will aim to uncover why specific skull shapes are better at catching certain prey using bioengineering computer simulations.
-end-


Monash University

Related Dolphins Articles:

Exeter researchers help protect Peru's river dolphins
River dolphins and Amazonian manatees in Peru will benefit from new protection thanks to a plan developed with help from the University of Exeter.
New study defines the environment as an influencer of immune system responses in dolphins
Two populations of wild dolphins living off the coast of Florida and South Carolina are experiencing more chronically activated immune systems than dolphins living in controlled environments, raising concerns of researchers about overall ocean health, and the long-term health of bottlenose dolphins.
Immature spinner dolphin calf SCUBA tanks spell disaster in tuna fisheries
Dolphins that live in the deep ocean have well developed oxygen storage, but now it turns out that spinner dolphin calves do not develop their SCUBA capacity any faster than coastal species, despite their deep diving lifestyle.
The latest HKU study clarifies how many dolphins there are in Hong Kong waters
The latest study by researchers at the University of Hong Kong (HKU) delivered the first-ever comprehensive population assessment of the Chinese white dolphins that inhabit Hong Kong waters, and what they found differs from the common public belief.
Crocodiles and dolphins evolved similar skulls to catch the same prey: Study finds
A new study involving biologists from Monash University Australia has found that despite their very different ancestors, dolphins and crocodiles evolved similarly shaped skulls to feed on similar prey.
Cutting-edge cameras reveal the secret life of dolphins
A world-first study testing new underwater cameras on wild dolphins has given researchers the best view yet into their hidden marine world.
Dolphins following shrimp trawlers cluster in social groups
Bottlenose dolphins near Savannah, Georgia are split into social groups according to whether or not they forage behind commercial shrimp trawlers, according to a study published Feb.
Scientists studying dolphins find Bay of Bengal a realm of evolutionary change
Marine scientists have discovered that two species of dolphin in the waters off Bangladesh are genetically distinct from those in other regions of the Indian and western Pacific Oceans, a finding that supports a growing body of evidence that the Bay of Bengal harbors conditions that drive the evolution of new life forms, according to a new study by the American Museum of Natural History(AMNH), WCS (Wildlife Conservation Society), and the cE3c -- Centre for Ecology, Evolution and Environmental Changes (Universidade de Lisboa).
Researchers probing the beneficial secrets in dolphins' proteins
Why reinvent the wheel when nature has the answer? That's what researcher Michael Janech, Ph.D. of the Medical University of South Carolina, has found to be true, drawing from the field of biomimicry where researchers look to nature for creative solutions to human problems.
Former pesticide ingredient found in dolphins, birds and fish
A family of common industrial compounds called perfluoroalkyl substances, which are best known for making carpets stain resistant and cookware non-stick, has been under scrutiny for potentially causing health problems.

Related Dolphins Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Climate Crisis
There's no greater threat to humanity than climate change. What can we do to stop the worst consequences? This hour, TED speakers explore how we can save our planet and whether we can do it in time. Guests include climate activist Greta Thunberg, chemical engineer Jennifer Wilcox, research scientist Sean Davis, food innovator Bruce Friedrich, and psychologist Per Espen Stoknes.
Now Playing: Science for the People

#527 Honey I CRISPR'd the Kids
This week we're coming to you from Awesome Con in Washington, D.C. There, host Bethany Brookshire led a panel of three amazing guests to talk about the promise and perils of CRISPR, and what happens now that CRISPR babies have (maybe?) been born. Featuring science writer Tina Saey, molecular biologist Anne Simon, and bioethicist Alan Regenberg. A Nobel Prize winner argues banning CRISPR babies won’t work Geneticists push for a 5-year global ban on gene-edited babies A CRISPR spin-off causes unintended typos in DNA News of the first gene-edited babies ignited a firestorm The researcher who created CRISPR twins defends...