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:

Good night? Satellite data uncovers dolphins on the move at nighttime
More than 1,000 bottlenose dolphins live in Florida's Indian River Lagoon year-round.
Cooperative male dolphins match the tempo of each other's calls
When it comes to working together, male dolphins coordinate their behavior just like us.
Lehigh University engineers unlock secrets to swimming efficiency of whales, dolphins
Lehigh University MechE professor Keith Moored is PI on a recent Journal of the Royal Society Interface paper on work examining the fluid mechanics of cetacean propulsion by numerically simulating their oscillating tail fins.
HKU scientists find high concentrations of toxic phenyltin compounds in local Chinese white dolphins
An HKU research team confirmed the occurrence of biomagnification of toxic substance TPT compounds along the marine food chain resulted in very high concentrations of TPT in two top predators, the Chinese white dolphin and the finless porpoises.
Dolphins gather in female family groups
Social clusters including mothers' groups play an important role in the life of southern Australian bottlenose dolphins, a new study shows.
Lights on fishing nets save turtles and dolphins
Placing lights on fishing nets reduces the chances of sea turtles and dolphins being caught by accident, new research shows.
Genes 'lost' in whales and dolphins helped their ancestors transition to life underwater
When cetaceans (whales, dolphins, and porpoises) transitioned from life on land to life in the sea about 50 million years ago, 85 genes became inactivated in these species, according to a new study.
Antibiotic resistance surges in dolphins, mirroring humans
Scientists obtained a total of 733 pathogen isolates from 171 individual wild Bottlenose dolphins in Florida and found that the overall prevalence of resistance to at least one antibiotic for the 733 isolates was 88.2%.
Environment: Pollutants found in skin and blubber of English Channel dolphins
High levels of pollutants, such as industrial fluids and mercury, may have accumulated in the blubber and skin of one of the largest coastal populations of dolphins in Europe, a study in Scientific Reports indicates.
Dolphins form friendships through shared interests just like us, study finds
When it comes to making friends, it appears dolphins are just like us and form close friendships with other dolphins that have a common interest.
More Dolphins News and Dolphins Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Processing The Pandemic
Between the pandemic and America's reckoning with racism and police brutality, many of us are anxious, angry, and depressed. This hour, TED Fellow and writer Laurel Braitman helps us process it all.
Now Playing: Science for the People

#568 Poker Face Psychology
Anyone who's seen pop culture depictions of poker might think statistics and math is the only way to get ahead. But no, there's psychology too. Author Maria Konnikova took her Ph.D. in psychology to the poker table, and turned out to be good. So good, she went pro in poker, and learned all about her own biases on the way. We're talking about her new book "The Biggest Bluff: How I Learned to Pay Attention, Master Myself, and Win".
Now Playing: Radiolab

Invisible Allies
As scientists have been scrambling to find new and better ways to treat covid-19, they've come across some unexpected allies. Invisible and primordial, these protectors have been with us all along. And they just might help us to better weather this viral storm. To kick things off, we travel through time from a homeless shelter to a military hospital, pondering the pandemic-fighting power of the sun. And then, we dive deep into the periodic table to look at how a simple element might actually be a microbe's biggest foe. This episode was reported by Simon Adler and Molly Webster, and produced by Annie McEwen and Pat Walters. Support Radiolab today at Radiolab.org/donate.