Researchers have found that determining the sex of a dinosaur is almost impossible. Scientific work published in the journal PeerJ.
Despite previous claims by scientists about success in determining gender in dinosaurs, a current study by Queen Mary of the University of London showed that it is almost impossible to determine gender differences in ancient reptiles.
The new study analyzed the skulls of modern, endangered gharials (fish-eating crocodiles) and giant crocodile species to determine how easy it is to distinguish males and females using only fossil records.
The male gavialis are larger in size than the females and have a fleshy outgrowth at the end of their mouths, known as “ghara” (the name is given to an Indian clay pot that this outgrowth looks like). Since the ghara consists of soft tissues, it is supported by the bone cavity near the nostrils – the narial fossa, which can be identified on the turtles of the gavials.
The research team, which included Jordan Mallon of the Canadian Museum of Nature, Patrick Hennessey of the University of South George and Lawrence Whitmer of the University of Ohio, studied 106 specimens of gavials in museums around the world. They found that, in addition to the presence of lower pits in males, it is very difficult to distinguish the sex of the reptile.
Dr. David Hon, a senior lecturer in zoology at Queen Mary University of London and the author of the study, says: “Like dinosaurs, gavials are large, slow-growing reptiles that lay their eggs, making them a good model for studying extinct dinosaurs. Our studies show that even with prior knowledge of the sex of the sample, it is still difficult to distinguish between males and females of gavial. With most dinosaurs, we don’t have enough data to use for this study, and we can’t figure out the gender of the ancient reptile”.
In addition, in many species, females and males are very different from each other. For example, horns are mainly found only in deer males, and in peacocks, males are usually brightly colored and have a beautiful tail. This feature is known as sexual dimorphism, and is very common in the animal kingdom. Scientists believe that dinosaurs also demonstrate these differences, but in most cases it is too difficult to determine only by the skeleton.
Dr. Hon said: “Some animals exhibit an unusually high level of sexual dimorphism, for example, huge differences in size between males and females. The gavials are somewhere in the middle, as they have these large narial fossae that can help with identification. The differences between dinosaurs are really striking, or if there was such a clear feature as a fossa, we would easily distinguish between male and female dinosaurs using existing skeletons”.
The new study also casts doubt on previous ones that hinted at gender differences in popular dinosaur species such as the tyrannosaurus rex and led to widespread misconceptions among the general public.
“Many years ago, in a scientific article it was said that there are more female Ti-rex than males. But our results show that the level of data available is simply not enough to make this conclusion, ”Dr. Hon concludes.