Remingtonocetids were an early branch of the whale evolutionary family tree, known from about 49-41 million years ago and splitting off somewhere between the famous “walking whale” Ambulocetus and the more oceanic protocetids. With otter-like bodies, tiny eyes, and long gharial-like snouts, they lived in near-shore shallow marine habitats and probably swam using a combination of their hind feet and tails.
They were initially found only in Pakistan and India, but then Rayanistes afer here was discovered all the way over in Egypt – suggesting that these early whales were much more widespread than previously thought, dispersing through the Tethys Sea at about the same time as their protocetid cousins.
Dating to the Middle Eocene (~45-41 mya), Rayanistes was probably about 2.5m long (8′2”). It had powerful hindlimb musculature that would have given it a very strong kicking swimming stroke, but it probably couldn’t actually support its own weight on land since its femur wasn’t very well anchored into its pelvis.
Cycnorhamphus suevicus, a pterosaur from the Late Jurassic of Germany and France (~150-145 mya).
It had a wingspan of about 1.3m (4′3″), and was originally thought to look similar to Pterodactylus with long straight jaws – but a well-preserved fossil nicknamed “the Painten Pelican” revealed its snout was actually much more oddly-shaped.
It turns out Cycnorhamphus’s jaws arced outwards, creating an opening that seems to have become more pronounced as individuals reached adulthood. Soft-tissue impressions in the fossil also show some sort of stiff “flanges” on each side of the upper jaws, covering the gap and giving it a sort of bulldog-like appearance.
The function of this jaw structure is unknown for certain, but it’s been speculated to be a specialization for cracking open hard-shelled prey like molluscs.
Enantiophoenix electrophyla, an enantiornithean bird from the Late Cretaceous of Lebanon (~95 mya).
It was similar in size to a modern starling, around 20cm (8″) long, and although only known from a fragmentary fossil it had fairly chunky leg bones with large claws. It was probably a strong percher like most other avisaurid enantiornitheans.
Several tiny pieces of amber were also found within the fossil, which have been suggested to be stomach contents. This could perhaps be evidence of Enantiophoenix feeding on tree sap like modern sapsuckers, but without a known skull it’s hard to tell for certain whether it was specialized for that sort of diet or not.
Eretmorhipis carrolldongi, a hupehsuchian marine reptile from the Early Triassic of China (~247 mya).
This species was originally named back in 2015, but at the time the only known specimens were missing their heads. It was assumed that its skull would have looked similar to those of other hupehsuchians… but now new fossils have been found, and it seems to have actually been much much weirder!
Eretmorhipis’ head was surprisingly tiny in proportion to its body – sort of like a marine version of Cotylorhynchus – and its shape convergently resembled the modern platypus, with a wide “duck bill” and very small eyes. It may have hunted for food along the seafloor in a similar manner to the platypus, using either a highly sensitive sense of touch or possibly even electroreception to locate small invertebrates like worms and shrimp.
It also had much larger bony osteoderms than its other known hupehsuchian relatives, forming a distinctive protruding spiky ridge down its back. At about 85cm in length (2′9″) it was one of the largest marine animals around at the time, so this structure probably wasn’t needed for defense – but as with other hupehsuchians its actual function is still unknown.