#ecdysozoans — Public Fediverse posts

Today's xkcd reminded me of the progression where insects' ancestors evolved out of the water to escape the ancestors of spiders. Who evolved to follow them. And that insects then evolved wings, in part to escape spiders, some of whom evolved webs that catch fliers.

Side note: Spiracles are amazing. https://xkcd.com/3199/ #arthropods #ecdysozoans

Rare #fossil embryos show early #Ecdysozoa development in #Cambrian era https://phys.org/news/2024-12-rare-fossil-embryos-early-ecdysozoa.html paper: https://www.sciencedirect.com/science/article/abs/pii/S0031018224006242

"it suggests a bag-shaped body is likely primitive for #ecdysozoans (a diverse group of #animals including #roundworms, velvet #worms, #insects, and #crabs), while a vermiform body, characteristic of crown-group ecdysozoans, evolved later."

"Early evolution of the ecdysozoan body plan", Wang et al. 2024
https://elifesciences.org/reviewed-preprints/94709

A study that analyses fossils of early molting animals, and concludes that:

"ancestral ecdysozoans may have been non-vermiform animals."

#ecdysozoans are a group of animals that molt, and include nematodes and arthropods.

By the spikes you can tell this species was subject to heavy predation.