About 163 million years ago, a winged beast with elongated teeth died in what's now southern England. One of its fossilized lower jawbones was eventually recovered and by 1878, this prehistoric prize had found its way to London's world-class Natural History Museum.
The fossil was placed in a collections room drawer, where it attracted very little attention — until now. As a November 2018 paper explains, the long-ignored bone is way more significant than anyone realized. Apparently, it came from a hitherto unknown species of flying reptile. Named Klobiodon rochei by its discoverers, the animal used some wicked fangs to capture seafood dinners.
Tale of the Teeth
Published late last year in the journal Acta Paleontologica Electronica, the new paper was the Ph.D. thesis of one Michael O'Sullivan, a paleontologist at the University of Portsmouth. Co-written by David Martill, O'Sullivan's Ph.D. supervisor, the thesis is an overview of the various pterosaurs that inhabited present-day Great Britain 168 to 166 million years ago during the middle of the Jurassic period.
The pterosaurs were a hugely successful order of flying reptiles that co-existed with the non-avian dinosaurs before a mass extinction wiped out both groups 66 million years ago. (Note that pterosaurs were not dinosaurs themselves.)
Mid-Jurassic England was teeming with the flighted creatures. We know this because the Tanyton Limestone Formation — also known as the "Stonesfield Slate" — in Oxfordshire and Glocestershire has yielded the bones of more than 200 pterosaurs who lived at that point in time. The newly released study chronicles the diversity of species that've been found in those Tanyton deposits.
From southern England, the Stonesfield Slate pterosaur bones have been exported to various museums in Australia, the United States and Great Britain. While combing through the collections at London's Natural History Museum, O'Sullivan examined the jawbone in question.
"It first occurred to me that [this represented] a new species ... when I noticed the distinct shape of the teeth," O'Sullivan says in an email. The jawbone measures 5.5 inches (14 centimeters) long and is thought to be 88 percent complete, although the back end is missing. A diverse assortment of teeth are present, including some needle-like beauties that stretch up to 1 inch (2.6 centimeters) long.
"The back teeth were short but thick, while the front teeth formed elongate fangs that would have meshed together to form a grab or cage to help catch prey," O'Sullivan says. "Only one other Jurassic pterosaur, Dorygnathus, had a similar arrangement but its back teeth were much smaller ... it had thinner fangs and possessed a noticeably shallower jaw."
A Murky Backstory
Those dental quirks told O'Sullivan and Martill that they were looking at a unique pterosaur. A section of their paper describes the beast in detail and unveils its formal name. Klobiodon means "cage tooth" in Greek and rochei is a tip of the hat to comic book artist Nick Roche, who likes to use prehistoric animals as his muses.
O'Sullivan and Martill are by no means the first scientists to lay eyes on this wonderful little jawbone. How it originally came to light is a mystery. The fossil was first mentioned in an 1878 list of the Natural History Museum's acquisitions. According to said document, the fossil was donated by the English naturalist Robert Marsham, who'd died 81 years earlier.
"So there's quite a gap in the fossil's history and we'll probably never know when it was acquired," O'Sullivan says. He adds that in the year 1888 it was misidentified as a Rhamphocephalus, a pterosaur genus that's no longer deemed scientifically valid. (One alleged Rhamphocephalus fossil turned out to be a "poorly preserved crocodile skull.")
Everything we know about Klobiodon comes from that single, tooth-lined jawbone. O'Sullivan tells us there's another fossil out there, a "jaw tip with similar depth and curvature," that might represent a second Klobiodon specimen. Yet because the bone lacks teeth, scientists can't be sure about its identity.
Fishing on the Fly
The good news is that in paleontology, one fossil can tell you a lot. Pterosaurs are divided into two factions. Giants like Pteranodon of "Jurassic World" fame are classified as pterodactyloids, a group that's recognizable by their large skulls, extended palm bones and generally short tails. Many of them were toothless, and those who weren't tended to have uniform-looking teeth.
Klobiodon's dentition tells us that it belonged to that other gang: The rhamphorhynchoids. By comparing its isolated jaw to more complete rhamphorhynchoid fossils, O'Sullivan and Martill estimate that a full-grown Klobiodon would've had a 6.5-foot (2-meter) wingspan.
In Klobiodon's heyday, global sea levels were higher and Great Britain was a series of tropical islands. Rhamphorhynchoids who lived in coastal environments have been discovered with fish bones in their stomachs. Likewise, Klobiodon probably snatched up fish, squid and other marine animals with its cage-like maw.
"They may have had a similar ecological role as modern gulls and might have used comparable hunting techniques such as plucking fish from the sea on the wing, fishing while sitting on the surface of the water or perhaps performing shallow dives," O'Sullivan explains. "It's also likely Klobiodon would have supplemented its diet by hunting animals like small dinosaurs or early mammals if it had the opportunity."
The Stonesfield Slate deposits are world-famous for their ammonite and marine reptile fossils. Historically, the local pterosaur bones haven't received as much attention from scientists. With their comprehensive new study, O'Sullivan and Martill demonstrate that Stonesfield's crop of flying reptiles was way more diverse than many paleontologists previously thought. By looking at Klobiodon and its winged contemporaries, we can broaden our knowledge of pterosaur evolution.