Nav: Home

Can we really tell male and female dinosaurs apart?

May 12, 2020

Scientists worldwide have long debated our ability to identify male and female dinosaurs. Now, research led by Queen Mary University of London has shown that despite previous claims of success, it's very difficult to spot differences between the sexes.

In the new study, researchers analysed skulls from modern-day gharials, an endangered and giant crocodilian species, to see how easy it is to distinguish between males and females using only fossil records.

Male gharials are larger in size than females and possess a fleshy growth on the end of their snout, known as a ghara. Whilst the ghara is made from soft tissue, it is supported by a bony hollow near the nostrils, known as the narial fossa, which can be identified in their skulls.

The research team, which included Jordan Mallon from the Canadian Museum of Nature, Patrick Hennessey from Georgia Southern University and Lawrence Witmer from Ohio University, studied 106 gharial specimens in museums across the world. They found that aside from the presence of the narial fossa in males, it was still very hard to tell the sexes apart.

Dr David Hone, Senior Lecturer in Zoology at Queen Mary University of London and author of the study, said: "Like dinosaurs, gharials are large, slow growing reptiles that lay eggs, which makes them a good model for studying extinct dinosaur species. Our research shows that even with prior knowledge of the sex of the specimen, it can still be difficult to tell male and female gharials apart. With most dinosaurs we don't have anywhere near that size of the dataset used for this study, and we don't know the sex of the animals, so we'd expect this task to be much harder."

In many species, males and females can look very different from each other. For example, antlers are largely only found in male deer and in peacocks, males are normally brightly-coloured with large, iridescent tail feathers whereas females are much more subdued in their colouration. This is known as sexual dimorphism and is very common within the animal kingdom. It is expected that dinosaurs also exhibit these differences, however this research suggests that in most cases this is far too difficult to tell from the skeleton alone.

Dr Hone said: "Some animals show extraordinarily high levels of sexual dimorphism, for example huge size differences between males and females. Gharials sit somewhere in the middle as they do possess these large narial fossa that can help with identification. Our study suggests that unless the differences between the dinosaurs are really striking, or there is a clear feature like the fossa, we will struggle to tell a male and female dinosaur apart using our existing dinosaur skeletons."

The new research also challenges previous studies that have hinted at differences between the sexes in popular dinosaur species such as the Tyrannosaurus rex (T. rex), and led to common misconceptions amongst the general public.

"Many years ago, a scientific paper suggested that female T. rex are bigger than males. However, this was based on records from 25 broken specimens and our results show this level of data just isn't good enough to be able to make this conclusion," Dr Hone added.
-end-
Notes to Editors

Research publication: 'Ontogeny of a sexually selected structure in an extant archosaur Gavialis gangeticus (Pseudosuchia: Crocodylia) with implications for sexual dimorphism in dinosaurs' D Hone, J Mallon, P Hennessey, L Witmer. PeerJ

Supporting images available on request.

For a copy of the paper, please contact:

Sophie McLachlan
Faculty Communications Manager (Science & Engineering)
Queen Mary University of London
sophie.mclachlan@qmul.ac.uk
Tel: 020 7882 3787

About Queen Mary

Queen Mary University of London is a research-intensive university that connects minds worldwide. A member of the prestigious Russell Group, we work across the humanities and social sciences, medicine and dentistry, and science and engineering, with inspirational teaching directly informed by our world-leading research. In the most recent Research Excellence Framework we were ranked 5th in the country for the proportion of research outputs that were world-leading or internationally excellent. We have over 25,000 students and offer more than 240 degree programmes. Our reputation for excellent teaching was rewarded with silver in the most recent Teaching Excellence Framework. Queen Mary has a proud and distinctive history built on four historic institutions stretching back to 1785 and beyond. Common to each of these institutions - the London Hospital Medical College, St Bartholomew's Medical College, Westfield College and Queen Mary College - was the vision to provide hope and opportunity for the less privileged or otherwise under-represented. Today, Queen Mary University of London remains true to that belief in opening the doors of opportunity for anyone with the potential to succeed and helping to build a future we can all be proud of.

Queen Mary University of London

Related Dinosaurs Articles:

Finding a genus home for Alaska's dinosaurs
A re-analysis of dinosaur skulls from northern Alaska suggests they belong to a genus Edmontosaurus, and not to the genus recently proposed by scientists in 2015.
Can we really tell male and female dinosaurs apart?
Scientists worldwide have long debated our ability to identify male and female dinosaurs.
In death of dinosaurs, it was all about the asteroid -- not volcanoes
Volcanic activity did not play a direct role in the mass extinction event that killed the dinosaurs, according to an international, Yale-led team of researchers.
Discriminating diets of meat-eating dinosaurs
A big problem with dinosaurs is that there seem to be too many meat-eaters.
Jurassic dinosaurs trotted between Africa and Europe
Dinosaur footprints found in several European countries, very similar to others in Morocco, suggest that they could have been dispersed between the two continents by land masses separated by a shallow sea more than 145 million years ago.
In the shadow of the dinosaurs
Research published this Wednesday in Scientific Reports describes Clevosaurus hadroprodon, a new reptile species from Rio Grande do Sul state in southern Brazil.
When the dinosaurs died, lichens thrived
When the asteroid hit, dinosaurs weren't the only ones that suffered.
Dinosaurs were thriving before asteroid strike that wiped them out
Dinosaurs were unaffected by long-term climate changes and flourished before their sudden demise by asteroid strike.
Want to learn about dinosaurs? Pick up some Louisiana roadkill
Scientists are able to learn about an animal's ecosystem by studying the chemical makeup of its body, whether the animal died recently or millions of years ago.
How did alvarezsaurian dinosaurs evolve monodactyl hand?
An international research team led by XU Xing from the Institute of Vertebrate Palaeontology and Palaeoanthropology announced the discovery of two new Chinese dinosaurs: Bannykus and Xiyunykus, in the journal Current Biology, which shed light on how alvarezsaurian dinosaurs reduced and lost their fingers.
More Dinosaurs News and Dinosaurs 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

Our Relationship With Water
We need water to live. But with rising seas and so many lacking clean water – water is in crisis and so are we. This hour, TED speakers explore ideas around restoring our relationship with water. Guests on the show include legal scholar Kelsey Leonard, artist LaToya Ruby Frazier, and community organizer Colette Pichon Battle.
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

Uncounted
First things first: our very own Latif Nasser has an exciting new show on Netflix. He talks to Jad about the hidden forces of the world that connect us all. Then, with an eye on the upcoming election, we take a look back: at two pieces from More Perfect Season 3 about Constitutional amendments that determine who gets to vote. Former Radiolab producer Julia Longoria takes us to Washington, D.C. The capital is at the heart of our democracy, but it's not a state, and it wasn't until the 23rd Amendment that its people got the right to vote for president. But that still left DC without full representation in Congress; D.C. sends a "non-voting delegate" to the House. Julia profiles that delegate, Congresswoman Eleanor Holmes Norton, and her unique approach to fighting for power in a virtually powerless role. Second, Radiolab producer Sarah Qari looks at a current fight to lower the US voting age to 16 that harkens back to the fight for the 26th Amendment in the 1960s. Eighteen-year-olds at the time argued that if they were old enough to be drafted to fight in the War, they were old enough to have a voice in our democracy. But what about today, when even younger Americans are finding themselves at the center of national political debates? Does it mean we should lower the voting age even further? This episode was reported and produced by Julia Longoria and Sarah Qari. Check out Latif Nasser's new Netflix show Connected here. Support Radiolab today at Radiolab.org/donate.