Podcast 119 - Dimorphic Dinosaurs

The gang discusses two papers that look at the complex issues surrounding the identification of sexual dimorphism in archosaurs (e.g. birds, dinosaurs, and alligators/crocodiles). Meanwhile, James has very strong opinions about Fat Tire beer, Amanda becomes lost in independent research, and Curt accidentally tears the podcast apart.

Up-Goer Five (James Edition):

The group looks at two papers that want to see whether animals that lived a long time ago are boys or girls. The first paper is looking at lots of small animals that could fly and had hard mouths. We find them in small, not so small, and big, and it has been suggested that the big ones were boys, the not so small ones were girls, and the small ones were young. Some of them have big back ends, and it was thought that maybe those that had big back ends were boys and those that did not have big back ends were girls. The paper thinks that maybe both boys and girls had big back ends, because they find big back ends on the young ones. The group however have seen another paper that thinks that boys did have big back ends and girls did not have big back ends and the small ones were actually a different type of flying animal with hard mouths.

The second paper is looking at trying to tell if big angry animals without hair were boys or girls. To do this they look at big angry animals that are around today and animals with hard mouths that are too big to fly that are around today. They show that big angry animals and animals with hard mouths that can sometimes fly grow different, and if you did not know which ones were boys or girls it is very different to tell which of the big angry animals are boys and girls. They show that most big angry animals without hair from a long time ago grow like big angry animals today, and so we should wait for a lot of facts before deciding if they are boys or girls, and that when we have thought we have found different things between boys and girls in the past we may have been looking at grown ups and babies.

References: 

 Hone, David WE, and Jordan C. Mallon. "Protracted growth impedes the detection of sexual dimorphism in non‐avian dinosaurs." Palaeontology 60.4 (2017): 535-545. 

 Peters, Winfried S., and Dieter Stefan Peters. "Life history, sexual dimorphism and ‘ornamental’feathers in the Mesozoic bird Confuciusornis sanctus." Biology letters (2009): rsbl20090574.