god i love aliens

by their very definition, they are gone forever

there are ones that were truly unique, like Polar Tropical Forests and Fern Prairies, that we just could not have today

but there were ones that have equivalents to today, as well, like the first savannahs and steppes of the Miocene - they just have earlier versions of the plants and animals

there were so many because there are so many today, and each one had its own flora and fauna and was glorious

There's the wetlands and forests of Hell Creek in the Latest Cretaceous

the bizarre Volcanic Lake Forests of the Jehol Biota

whatever the hell the Ediacaran Reefs were

the Scale Tree Swamp Forests of the Carboniferous

"Mesozoic 2" aka pre-human Aotearoa

the Western Interior Seaway dominated by Mosasaurs

that isn't what I mean by "Polar Tropical Forest"

I mean a tropical forest

at the poles

ie, the ecosystems present during the Paleocene-Eocene Thermal Maximum

we have fossils of plants that showcase how different tropical plant lifestyles had to be up at the poles because of the light weirdness

the important part is "tropical", not "wet/rainforest". those are two different things

it first evolved in the latest Cretaceous, but it didn't actually take over everywhere until the Miocene, when grasses that process light differently (look up C3 vs C4 photosynthesis) evolved and just took the fuck over the planet

before then, other plants formed the low ground cover over the earth, and in many places those plants were ferns - spread all over the ground and covering it, much like grass, but significantly less dense. Dirt would have been much more common everywhere.

Like the reefs of the late Devonian, which were made of stromatoporoids, which may have resembled corals but were actually a highly diverse extinct group of sponges!

This is one of my own reconstructions of a stromatoporoid reef off the coast of Devonian Australia (plus anachronistic underwater baited camera):

The Cretaceous also had some wild extinct reefs which are known as carbonate reefs and were dominated by a group of bivalve molluscs called rudists!

1% …

2% …