Communities

Writing
Writing
Codidact Meta
Codidact Meta
The Great Outdoors
The Great Outdoors
Photography & Video
Photography & Video
Scientific Speculation
Scientific Speculation
Cooking
Cooking
Electrical Engineering
Electrical Engineering
Judaism
Judaism
Languages & Linguistics
Languages & Linguistics
Software Development
Software Development
Mathematics
Mathematics
Christianity
Christianity
Code Golf
Code Golf
Music
Music
Physics
Physics
Linux Systems
Linux Systems
Power Users
Power Users
Tabletop RPGs
Tabletop RPGs
tag:snake search within a tag
answers:0 unanswered questions
user:xxxx search by author id
score:0.5 posts with 0.5+ score
"snake oil" exact phrase
votes:4 posts with 4+ votes
created:<1w created < 1 week ago
post_type:xxxx type of post
Search help
Notifications
Mark all as read
Q&A

Would a Longer PETM Save the Creodonts and the Mesonychians?

+0
−0

Some 55.8 million years ago, Earth underwent a really dramatic heat wave known as the Paleocene-Eocene Thermal Maximum, or PETM. What happened, exactly? We don't know how it happened, but we do know that within 20,000 years, the temperature climbed by five to eight degrees Celsius (or nine to 14 degrees Fahrenheit) and persisted for 200,000 years afterwards. Many animals responded to this change by downsizing, not only to better maneuver around the spreading jungles, but also to lose more heat more quickly.

You might think that this would be good news for the carnivores. While small miacids and viverravids were around long enough to witness the PETM, they did not become the modern order Carnivora until after the fact, 42 million years ago. Until then, they'd have to stay in the shadows of two other groups of carnivores--the creodonts, a group popularized by such megapredators as Hyaenodon and Simbakubwa; and the meat-eating ungulates known as mesonychians. The former died out 11 million years ago due to overspecialization, limited mobility and smaller and simpler brains, which made them unable to deal with the changing climate from one side and the onslaught of smarter, more flexible carnivorans on the other. The latter died out early in the Oligocene probably due to competition with the creodonts.

In this alternate Earth, the PETM lasted longer than in our timeline--three to four times longer. Many lifeforms couldn't take the extra heat. Coral reefs died out, taking another 25% of all marine species with them. Ginkgophyta, Cycadophyta and Gnetophyta became extinct with no living descendants, whereas only 38% of the conifer species and one-third of all angiosperm orders were gone. And the extra heat forced many animals--like the creodonts and mesonychians--to get smaller and smaller. Would this sort of downsizing make the creodonts and mesonychians smaller and more flexible, perhaps evolve into carnivores analogous to cats, dogs, bears, pandas, skunks, weasels, raccoons, linsangs, civets, hyenas and mongeese, thus surviving well into the present day?

Why does this post require moderator attention?
You might want to add some details to your flag.
Why should this post be closed?

This post was sourced from https://worldbuilding.stackexchange.com/q/175734. It is licensed under CC BY-SA 4.0.

0 comment threads

0 answers

Sign up to answer this question »

This community is part of the Codidact network. We have other communities too — take a look!

You can also join us in chat!

Want to advertise this community? Use our templates!

Like what we're doing? Support us! Donate