The swimming reptile Polycotylus, viewed from the top. New discoveries indicate these prehistoric marine reptiles were quite chunky - more like seals and walruses than snakes or crocodiles. Polycotylus was a distant relative of the enormous Kronosaurus.
ELASMOSAURUS “Thin plate lizard” Late Cretaceous, 80.5 million years ago
Elasmosaurus was a plesiosaur that could grow up to 46 feet
in length – half of that length being neck! When first discovered in 1868, the
prominent paleontologist Edward Drinker Cope mistook its attenuated neck for a
tail, placing its head on its rear end. Cope’s professional rival, Othniel
Charles Marsh, ridiculed him for this error, marking the scientific community’s
first usage of “butthead” in peer review.
The endangered Pacific leatherback sea turtle, which makes an epic ocean-crossing journey each year to feast on sea nettle jellies off the California coast, is now the state’s official marine reptile. Gov. Jerry Brown signed the designation into law last week.
The Monterey Bay Aquarium was among the many ocean conservation organizations that supported the designation, introduced by Assemblymember Paul Fong of Mountain View. Fong was also the co-author of Aquarium-sponsored legislation that outlawed the shark fin trade in California.
Leatherback sea turtles are regular visitors to Monterey Bay. (That’s where staff member Alison Barratt took the photo above.) They make a 12,000-mile round trip journey from Indonesia to fatten up on jellies off our coast. Newly published research suggests that sea turtles may be able to sniff out the presence of ocean upwelling, which triggers the jellyfish blooms that turtles find so irresistible.
Unfortunately, longline fishing and development on leatherback nesting beaches have pushed this ancient reptile to the brink of extinction. We’re hoping its new status will bring attention to the threats facing leatherbacks and other sea turtles – and spark greater support for global conservation efforts.
ATOPODENTATUS “Absurd tooth” Middle
Triassic, 240 million years ago
This marine reptile bore a superficial resemblance to a sea lion or manatee (though
it had four limbs, distinct from its tail). It had a flamingo-like beak lined
with needle-like teeth, and a very unique, zipper-like cleft up the center of
its top jaw, both of which lead scientists to believe it was a filter-feeder.
It was given the name “absurd tooth,” presumably behind its back.
This large male Green sea turtle came into the reef for a much needed clean. I took a couple photos and then just sat with it for ten minutes as it got cleaned. It must have been at sea for a long time to be this dirty, or maybe it keeps getting creeped out by people staring at him every time he tries to get cleaned. It was such an old turtle, I cried I was so happy to share a moment with such an amazing creature. Currently listed as Endangered by the IUCN Red list.
MOSASAURUS “Lizard of the Meuse River” Late Cretaceous, 70-66 million years ago
Mosasaurus was a type of extinct marine reptile similar to a giant monitor lizard, but with fins. It would have been an apex predator of the Cretaceous seas, growing to almost 60 feet long! The first Mosasaurus fossil was found in 1764 (about 50 years before the first dinosaur remains), though it wasn’t recognized as a marine reptile until around 1800 (roughly 40 years before the term “dinosaur” was coined). While it was instrumental in the understanding of extinction – and by extension modern biology as we know it – Mosasaurus was largely forgotten until its triumphant rediscovery in November 2014 as part of a movie trailer.
While the era of dinosaurs is now fairly fixed in the popular consciousness, far less attention is given to the reptiles of the same time period that returned to the sea. While not dinosaurs, these reptiles too reached impressive proportions- and gained traits, like live birth and warm-bloodedness, that we now associate with mammals.
Take my hand and I’ll walk you through the world of seafaring reptiles, all the way back to diminutive Mesosaurus 300 million years ago…
ICHTHYOSAURUS “Fish lizard” Late Triassic-early Jurassic, 206-180 million years ago
Though it lived at the same time, Ichthyosaurus was not a dinosaur. And
though it looks a bit like a modern dolphin, it wasn’t a mammal (or even a fish!). Ichthyosaurus was a reptile, and it lends
its name to an entire group of similar marine reptiles: the ichthyosaurs (“fish lizards”). Ichthyosaurs
mostly ate fish, and probably hunted near the water’s surface using their large
eyes. And, based on juvenile fossils found inside adults, they gave birth to
live young, just like your mother. Ohhhhhhh.