Palaeo After Dark

The gang discusses two papers that talk about T-Rex, and also the interesting way that these papers were discussed in popular culture. The first paper looks at the walking speed of T-Rex, and the second paper estimates how many T-Rex could have lived on Earth at any given time. Meanwhile, James is so very tired, Amanda loves soap, and Curt picks the worst transitions.

 

Up-Goer Five (Curt Edition):

The friends talk about a big angry animal that a lot of people know about. The first paper looks at how quickly that big angry animal could walk. Most animals with four legs / arms all walk about as fast as each other, even if the animals are big or small. Early work had made it seem that the big angry animal may have walked faster than the animals today. These early papers were looking at the foot falls of these big angry animals. This new paper looks at the big long part that comes off the end of these angry animals. The paper says that these big angry animals walked about as fast as any animal today even though they were big and angry and walked in a funny way.

The second paper tries to use the parts of these big angry animals that have turned into rocks to try and figure out how many of these big angry animals may have been living at any given time. It looks at how many animals we see around today to do this, and sees that the number of animals may be controlled by how much food the animals need to keep eating. Some animals burn a lot of food which means there can not be as many of them in an area. This means you can use how much food an animal burns to try and figure out how many animals could have been living in an area at any time. So they use this and some other numbers to try and figure out how many of these big animals were around in the past. This also allows them to figure out how many of the big angry animals may have been covered in ground and have their parts turned to rocks and how many were not.

 

References:

Marshall, Charles R., et al. "Absolute abundance and preservation rate of Tyrannosaurus rex." Science 372.6539 (2021): 284-287.

van Bijlert, Pasha A., AJ ‘Knoek van  Soest, and Anne S. Schulp. "Natural Frequency Method: estimating the  preferred walking speed of Tyrannosaurus rex based on tail natural  frequency." Royal Society Open Science 8.4 (2021): 201441.

Direct download: Podcast_212_-_Ruining_T-Rex.mp3
Category:general -- posted at: 3:00am EDT

The gang talks about two papers that look at changes in ecological interactions through deep time. The first paper looks at how ecological networks changed from the Permian into the Triassic, and the second paper looks at how echinoid diversity patterns compare to echinoid predation patterns. Meanwhile, James has some choice words about Elon Musk, Amanda’s stream is torn “into pieces”, and Curt once again would really like to start the second half of the podcast…

 

Up-Goer Five (Curt Edition):

Our friends talk about how animals and things that are not animals can build a place to live together, and how that changes over time. The first paper looks at how the places these animals and not animals build can change when things get really bad. It looks at two places in the past and uses numbers to see how these places change by getting more busy or less busy. They find that before most of the times when lots of stuff died, the places built by these animals and not animals were getting easy to fall to pieces. This is not true for this one time where things go really bad though, which is interesting and means that what was happening when things got really bad must be different.

The second paper looks at how a round animal in the water with hard hurt causing parts have changed over time and tries to see if being eaten caused some change. The paper finds that there are some changes that happen when we see these things get eaten, but also a lot of the changes are happening before we see these things get eaten.

 

References:

Petsios, Elizabeth, et al. "An  asynchronous Mesozoic marine revolution: the Cenozoic intensification of  predation on echinoids." Proceedings of the Royal Society B 288.1947 (2021): 20210400.

Huang, Yuangeng, et al. "Ecological  dynamics of terrestrial and freshwater ecosystems across three  mid-Phanerozoic mass extinctions from northwest China." Proceedings of the Royal Society B 288.1947 (2021): 20210148.

Direct download: Podcast_211_-_Fossil_Ecological_Networks.mp3
Category:general -- posted at: 3:00am EDT

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