Sun, 31 July 2022
The gang discusses two papers that look at what past sharks might have eaten. The first paper uses nitrogen isotopes to determine the trophic level of species belonging to the extinct shark genus Otodus, and the second paper shows evidence of predation/scavenging of sperm whales by sharks in the late Miocene. Meanwhile, James has a couch to burn, Curt proposes an experiment to find the best animal, Amanda becomes shark Nietzsche.
Up-Goer Five (Curt Edition):
Our friends look at two papers that look at what big angry animals with big teeth who breathe water and lived in the past could have eaten. The first paper looks at the parts of these animals from the past and uses what those parts of made of to try and see what kind of things they might have eaten. This is the first time that this has been done using these parts of the animal, since most of these kinds of papers look at living animals and so they can get parts that do not last when the animals die. It had been said that these big angry animals in the past may have eaten big animals that eat small things, and that they might have died out when there was less big animals that eat small things. This paper finds that the parts that make up these animals show that maybe these animals were eating things that ate other bigger things, that these big animals were probably not just eating this one type of animal but may have gone for anything, as well as other animals that also eat pretty much everything. One animal that they mention these big angry animals that breathe water could have eaten is a big animal with warm blood and big teeth that lives in water.
The second paper looks at how the hard parts of big animals with warm blood and big teeth that live in water at this time have hurt marks on their hard parts that look like they were from the teeth of big angry animals that breathe water. These hurt marks are along a part of the head that has a lot of stuff in it which animals would like to eat. The hurt marks are all different, with some that look like the animal bit them right on the head, and others look like marks from teeth that were biting at the body when it was already dead. It seems like many different types of angry animals with big teeth who breathe water may have been eating these animals with warm blood and big teeth.
Kast, Emma R., et al. "Cenozoic megatooth sharks occupied extremely high trophic positions." Science Advances 8.25 (2022): eabl6529.
Benites-Palomino, Aldo, et al. "Sperm whales (Physeteroidea) from the Pisco Formation, Peru, and their trophic role as fat sources for late Miocene sharks." Proceedings of the Royal Society B 289.1977 (2022): 20220774
Sun, 17 July 2022
The gang discusses two papers that look at the impact of the end Cretaceous mass extinction. The first paper looks at ecomorphospace changes in mosasaur communities prior to the extinction event, and the second paper discusses the importance of a large freshwater gar which lived through the recovery. Meanwhile, James has some new and interesting ecological theories, Curt is simpatico with his recording equipment, and Amanda acts as our resident “fish” expert.
Up-Goer Five (Curt Edition):
Our friends talk about two papers that look at a time when a big rock hit us a long long time ago. The first paper looks at how big angry animals in the water that you can not drink did before the big rock hit. There is a big question about if these big angry animals that live in water you can not drink were doing well before the big rock hit, or if they were already on their way out. This paper looks at how the heads of these animals changed over space and time by looking at a large number of these from lots of different places. What they find is that there is a lot going on before the big rock hit. Some places are having their big animals look like they are having real problems, but in other places there seems to be a lot of new change in these big animals. It seems that this time before the big rock was a time when these big animals were going through a lot of changes. The big rock may have hit at a very bad time because things were not calm because of all of these changing going on.
The second paper looks at animals living in water you can drink after the big rock hit. This paper finds a very large animal that breathes water head. Since this is a group of animals that are still around today, they can use the head to figure out how big the animal would have been, and they find that it would have been pretty big and also would have eaten other animals. This animal lived pretty soon after the big rock hit. This might mean that animals living on land and in the water that you can drink may have been doing a lot better than things living in the water you can not drink. If an animal was able to get that big eating other animals, it seems that these places were doing well. One of the ways animals respond when things get bad and foot is short is that they get smaller. Since we do not see that happening in this place, it could mean that places like this were not hit that bad when the rock hit.
MacLaren, Jamie A., et al. "Global ecomorphological restructuring of dominant marine reptiles prior to the Cretaceous–Palaeogene mass extinction." Proceedings of the Royal Society B 289.1975 (2022): 20220585.
Brownstein, Chase Doran, and Tyler R. Lyson. "Giant gar from directly above the Cretaceous–Palaeogene boundary suggests healthy freshwater ecosystems existed within thousands of years of the asteroid impact." Biology Letters 18.6 (2022): 20220118.
Sun, 3 July 2022
The gang discusses two papers that look at how combining fossil and modern data can affect our understanding of evolution. The first paper looks at studying primate biogeography, and the second paper studies how human interactions have affected dog morphology and disparity. Meanwhile, James finds a song he likes, Amanda could use some skin, and Curt appreciates how timely we’ve always been.
Up-Goer Five (Curt Edition):
Our friends look at two papers that show how using stuff from today and stuff from the past together can give you a better idea of what is going on with living things. The first paper looks at how we study where animals who look a lot like us lived in the past and how they came to live where they live today. The paper looks at how we can use old animals along with the animals around today to get a better idea of how the animals today got to where they are. That said, they do find that you need to take some care with the old animals you put in the study. You want to make sure that you really know what these old animals actually are. If not, it can make your study give weird answers. But, in the end, they show that it is better to use both old and today animals when you can.
The second paper looks at old dogs. Dogs can look like a lot of different things today. So people wanted to know if dogs could always look like so many different things in the past. So they found old parts of dogs from old human remains that date back to before people started to really change how dogs looked. They ran a study to see how different those dogs were from each other, and from dogs we have today, and also other things that are not dogs but are close to dogs. They find that these old dogs could be very different from each other, but not as different as the dogs we see today. They were a lot different from the other dog like animals too. So it shows that dogs were able to be very different in the past, but people have made this change even bigger.
Wisniewski, Anna L., Graeme T. Lloyd, and Graham J. Slater. "Extant species fail to estimate ancestral geographical ranges at older nodes in primate phylogeny." Proceedings of the Royal Society B 289.1975 (2022): 20212535.
Brassard, Colline, et al. "Unexpected morphological diversity in ancient dogs compared to modern relatives." Proceedings of the Royal Society B 289.1975 (2022): 20220147.