microscopic ostracods. they’re so cute! the first two have nodose orientation which makes the third one look super smooth and almost slimy by comparison. i’ll come back and label the genuses later :) these are crustaceans, which i think is CRAZY. probably the weirdest thing i learned in paleo is how extensive the arthropods are—i knew there were a lot of them, but the fact that these things are closely related to insects is wild. echinoderms are weird, sure, but at least they have a lot in common!
one of the questions on my paleo final was about distinguishing two-valved protists, brachiopods, bivalves, and ostracods. it seems unfair to me that bivalves get to be “bivalves” when there are so many two-valved organisms out there! i discussed the feeding structures and got a pretty good grade, so i assume i was on the right track there—although their external structure looks similar, what’s going on inside each of them is vastly different.

 

Hexagonaria, a genus of colonial rugose coral which dates to the Devonian period (~420 mya)