#paleocolor

Hassianycteris messelensis was an early bat that lived in what is now Germany during the mid-Eocene, about 47 million years ago.

It's generally considered to be very closely related to the common ancestry of modern bats – but a recent study suggests that the stem-bat evolutionary tree is actually quite a bit more complicated than previously thought.

It had a 35-40cm wingspan (~14"-16"), and thanks to the exceptional preservation of the Messel Pit fossil site we actually know some details about its external life appearance. One specimen preserves a soft-tissue impression of its ear shape, and fossilized melanosomes suggest that its fur was colored reddish-brown.

Its wing proportions indicate it was adapted to fly high and fast in open spaces, and its strong jaws and preserved gut contents show it mainly preyed on tough-shelled insects like beetles.

———

NixIllustration.com | Tumblr | Patreon

Greenwaltarachne pamelae was an orb-weaver spider that lived in what is now Montana, USA, during the mid-Eocene, around 46 million years ago.

Known from a single fossil of an adult female, it had a body length of about 2mm (~0.08") and a legspan of around twice that. The specimen is even well-preserved enough to show banded markings on the legs resembling those of some modern orb-weaver species.

It would have lived in what was then a rift valley with a tropical climate, along the shoreline of the ancient 160km long (~100 miles) Lake Kishenehn. It was part of a highly diverse ecosystem full of numerous other invertebrates – including miniscule fairyflies, and even mosquitoes with evidence of blood preserved inside their bodies – and a wide variety of mammals ranging from tiny rodents to large brontotheres.

———

NixIllustration.com | Tumblr | Patreon

The armor-headed placoderms were the dominant fish during the Devonian period, evolving a wonderfully diverse range of shapes and sizes, and occupying ecological niches in both marine and freshwater habitats.

Groenlandaspis antarctica here lived during the mid-to-late Devonian, about 383 million years ago, in the Oates Land region of Antarctica – at that time located further north than it is today, with the local climate being warm and subtropical.

It was a moderately-sized river-dwelling placoderm, around 50cm long (1'8"), and its bony armor formed a sort of pyramid shape with wing-like projections at its sides, a structure that would have acted as a hydrofoil and made it an efficient swimmer. Most of the armor plates were rigidly fused together, except for a hinge point between its head and thorax that allowed it to open its jaws, but unlike its more famous relative Dunkleosteus it couldn't gape its mouth open particularly wide. It may have been a bottom-feeder, grubbing around in muddy riverbeds and using its small but strong jaws to crush hard-shelled prey.

Various other species of the Groenlandaspis genus have been found all around the world, but there's something incredibly rare and special about Groenlandaspis antarctica in particular:

We actually know what color it was.

Preserved pigment cells in its fossils indicate that it was red on top and silvery-white on its underside in a countershaded pattern, camouflaging it in the murky silty waters of the ancient Antarctic rivers.

...And also made it look a bit like a prehistoric goldfish.

———

There’s no evidence for bioluminescence having ever evolved in reptiles (or any tetrapods for that matter), and while it being convergently evolved in marine reptiles isn’t outright impossible I’d still say it’s highly unlikely.

Thank you!