The gang discusses two papers that look at ecological patterns in the Mesozoic. The first paper looks at ecomorphic trends in Triassic herbivorous tetrapods, while the second paper uses morphological and chemical evidence to estimate the behavioral patterns of Cretaceous mosasaurs. Meanwhile, James has ideas about electrolites, Curt has a 99% average, and Amanda manages to record an entire podcast while having vertigo (that last bit isn’t a joke).

Up-Goer Five (Amanda Edition):

Today our friends talk about where and how things live. The first paper looks at all kinds of animals with four feet that eat green things from the first part of the age of big angry animals with lots of teeth and no hair. This paper is trying to use the parts of the animal's face to see how they eat. There are different kinds of ways to eat green things, and some ways of doing things have more types of these animals with four feet than others. They also find that there are big changes that happen at some times in different groups of these animals. The second paper is really cool and looks at big angry animals with hard skin that go back to the water. This paper shows that these big angry animals, which live in water that isn't good to drink, sometimes go to places where there is more water that is good to drink. Some go back to water that is good to drink every 4 to 7 days if they live in one place, or 12 to 20 days if they live in the other place. It is possible that these big angry animals with hard skin that go back to the water might have also gone from top of the world towards the middle of the world over longer times, and back again, like animals with light bodies and no teeth and no hair, but they are not sure here, they need to look more.

References:

Taylor, Leah Travis, et al. "Oxygen  isotopes from the teeth of Cretaceous marine lizards reveal their  migration and consumption of freshwater in the Western Interior Seaway,  North America." Palaeogeography, Palaeoclimatology, Palaeoecology 573 (2021): 110406.

Singh, Suresh A., et al. "Niche partitioning shaped herbivore macroevolution through the early Mesozoic." Nature communications 12.1 (2021): 1-13.

The gang discusses two papers that are loosely connected by the fact that they include mammals. The first paper looks at the biomechanics of a type of sabre tooth cat. The second paper analyzes the stability of mammal communities in deep time. Meanwhile, James loves the fans, Amanda is hemmed in by sound, Curt tries to avoid a lawsuit, and everyone really bungles explaining a paper on what is supposedly a scientific podcast.

Up-Goer Five (Curt Edition):

Our friends talk about two very different papers that are still about things with hair that are warm. The first paper looks at some of these animals with hair that had a set of very long teeth in their mouth that look like things we use to cut people. These animals all had many different types of long teeth, but we usually thought that they might be doing a lot of the same things just because so few other animals with hair get sets of teeth that long. This paper looks at the other parts of one of these animals with long teeth and finds that it is very different from many of the other animals with long teeth. A lot of animals with long teeth could run quick for a short time, while this animal looks like it could run for long times. This animal looks like it could chase things for a longer time, while the other animals with long teeth may have surprised their food. This is cool because it means that animals may have got long teeth for different reasons.

The second paper looks at groups of animals living together and sees how those groups change over time. They are looking to see if those groups can stay more or less the same across a long time, and also what helps these groups to not change. What they find is that in the area they are looking, there are three different groups that form and more or less stay the same until they suddenly change. These sudden changes happen when the world around them changes a lot. The groups remain more or less the same though before these really big changes in the world. Also, the groups can remain more or less the same even if the animals in those groups change over time. The thing that seems to be important in keeping these groups more or less the same is how the groups are built. Groups with a lot of different jobs for animals to do seem to be better at staying more or less the same over a long time.

References:

DeSantis, Larisa RG, et al. "Dietary ecology of the scimitar-toothed cat Homotherium serum." Current Biology (2021).

Blanco, Fernando, et al. "Punctuated ecological equilibrium in mammal communities over evolutionary time scales." Science 372.6539 (2021): 300-303.