One prehistoric crocodile-like reptile, for example, had seven fingers. And ancient whales called basilosaurids experienced enough bone integration that they were inching toward penguin territory. The nearly 16-foot long dolphin (Ankylorhiza tiedemani comb. N.) lived around 25 million years ago in what is now South Carolina, according to the study published last week in the journal Current. After this ancient dolphin went extinct about 23 million years ago, shark-toothed dolphins and giant killer sperm whales evolved to occupy Ankylorhiza's position within 5 million years. Giant killer sperm whales had massive teeth and likely preyed upon smaller whale species, while today's sperm whales eat mostly giant squid. Dolphin is a common name of aquatic mammals within the infraorder Cetacea.The term dolphin usually refers to the extant families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), and Pontoporiidae (the brackish dolphins), and the extinct Lipotidae (baiji or Chinese river dolphin). Experience a 4D movie, tour behind the scenes, meet aquatic animals and more with National Aquarium Tours & Experiences.
- Prehistoric Dolphin With Legs
- Prehistoric Dolphin Fossils
- Prehistoric Dolphin On Land
- Prehistoric Dolphin Types
When we think of palaeontology, the image that springs to mind is usually one of field researchers scratching and sifting through rock to uncover the remains of ancient creatures. But sometimes, new discoveries are waiting right under our noses, where they have been sitting for decades: in the collections of the world's museums.
Thanks to a scientist's keen eye, a newly identified type of 200-million-year-old ichthyosaur has just joined the roster of prehistoric marine reptiles.
The fossil in question belonged to a sea creature that lived alongside dinosaurs some 200 million years ago. They might look more like a dolphin or shark, but ichthyosaurs– a group of ancient beasts whose name roughly translates to 'fish lizard' – are more closely related to terrestrial reptiles.
University of Manchester honorary scientist Dean Lomax first came across the specimen while on a visit to Leicester’s New Walk Museum, where it had been resting since 1951. After giving the skeleton a thorough look, a few things caught Lomax’s eye.
“I knew it was unusual,' he says. 'It displays features in the bones that I had not seen before in Jurassic ichthyosaurs anywhere in the world. The specimen had never been published, so this rather unusual individual had been awaiting detailed examination,” says Lomax.
Ichthyosaurs cruised the world's waters during the Triassic, Jurassic and Cretaceous periods before finally going extinct around 90 million years ago. In fact, these animals were the very first large, extinct reptiles to be truly recognised by science – decades before the word 'dinosaur' was invented. But only a handful of the ocean giants are known from the lower Jurassic period, when this particular animal would have lived. That makes this discovery very exciting for palaeontologists like Lomax.
'Parts of the skeleton had previously been on long-term loan to ichthyosaur specialist and former museum curator Dr Robert Appleby,' adds Dr Mark Evans, palaeontologist and curator at New Walk Museum. '[It] only returned to the museum in 2004 after he sadly passed away. He was clearly intrigued by the specimen.'
MORE:Step aside, Nessie .. Fossils prove there was once a cooler sea monster in town
Although Appleby worked on the ichthyosaur for many years, he mistook it for a previously known species. This isn't entirely surprising as the skeleton itself, though near-complete, was a bit of a mishmash. It's thought that this animal took a nosedive into the sea floor in its final hours.
After close examination of the skeleton's caudal girdle (where tail meets body), Lomax determined that this animal is not only a new species, but also the first member of a new genus. Tasked with giving the specimen a permanent name, he opted to combine the names of two palaeontologists who inspired him over the years, Judy Massare and Bill Wahl. The behemoth is now officially known as Wahlisaurusmassare.
'I feel quite privileged to be able to study such fossils that have previously been collected and studied by palaeontologists from over 100 years ago,' adds Lomax. Lg apple screen mirroring download. 'My favourite thing about this kind of work is the fact that you never quite know what you’re going to discover. [You've got] a collection full of wonders that have been sitting there, awaiting rediscovery.'
Although thousands of specimens from this time have been discovered, this is the first new genus described in thirty years from the British early Jurassic. As is the case with all new fossil finds, the hope is that this newest member of the family could reveal more information on ichthyosaurs in general, and provide a clearer picture of their ecology and distribution.
'There are some stomach contents preserved in the specimen of W. massarae,' says Lomax. 'They have not been studied in detail yet, but it’s probable that they contain tiny hooklets from the arm tentacles of squid. Many other ichthyosaurs also have stomach contents preserved and they often contain squid hooks and fish scales, so it’s likely that Wahlisaurus also fed on squid and fish.'
Are any other new species of ichthyosaur hiding in museum collections? You can help scientists find out by donating here.
Top header image: Kevin Walsh/Flickr
More than 20 million years ago, the southern United States was home to a monstrous apex predator.
Researchers describe the full skeleton of a cetacean called Ankylorhiza tiedemani in a study published Thursday in the journal Current Biology. The 23-million-year-old bones indicate that a 15-foot-long dolphin with tusk-like front teeth once lived in present-day South Carolina. Its bones represent the first nearly complete skeleton of an extinct large dolphin.
The whale and dolphin ancestor dates back to the Oligocene and highlights an important step in the animals' evolution. Present-day cetaceans fall into two main categories:
Prehistoric Dolphin With Legs
- Toothed whales (odontocetes), which include dolphins, killer whales, porpoises, and narwhals
- Baleen (filter-feeding)whales, including right whale, blue whale, and gray whale
Lead study author Robert Boessenecker, a paleontologist at the College of Charleston, explains that before now, researchers believed that these two groups look similar today because they share ancestry — the idea being that a common ancestor would have a similar build. This skeleton throws a wrench in that theory.
'But Ankylorhiza, which is the first 'primitive' odontocete with a complete skeleton, lacks a number of features in modern cetaceans,' Boessenecker tells Inverse. Previously, researchers had only discovered a partial snout from the animal.
This study is a new, robust analysis of the skeleton, which was found in the 1990s by a commercial paleontologist, unearthed during a housing construction project. The creature's tail, teeth, humerus bone, and finger bones tell a new story of evolution. The early-diverging dolphin had already split from other whales before it developed more modern traits.
That means that modern toothed and baleen whales evolved separately to have shorter, narrower bones, among other features.
Ancient marine predator — This is researchers' first look at the complete skeleton of one of Earth's earliest dolphins.
The large-headed dolphin had big teeth, with front teeth that stuck out like tusks — possibly to jab at prey — and an oversized forehead. A dome at the front of its head may have helped with echolocation.
Prehistoric Dolphin Fossils
Similar to a sperm whale, Ankylorhiza tiedemani 'probably had somewhat stout pectoral fins,' Boessenecker says, rather than the sleek fins of a faster swimmer.
Prehistoric Dolphin On Land
Its teeth would have had thick roots and enamel ridges to cut through prey — a powerful image made even more striking because of its giant jaw muscles.
In ancient Charleston, the water was 'teeming with life,' Boessenecker says. Tuna, billfish, gannets, and 'the world's most diverse assemblage of dugongs' all thrived in the area.
Ankylorhiza was well-adapted to eating its way through all that biodiversity. The fierce hunter wasn't as large as today's killer whales, but it was double the size of most other dolphins at the time, and likely occupied a similar niche in its ecosystem. It ate smaller dolphins, large fish, sea turtles, seabirds, and possibly larger cetaceans, too.
Between the biodiversity of Charleston and the Oligocene serving as the moment when traits like filter-feeding and echolocation first evolved, 'the fossils from Charleston offer the most complete window into the early evolution of these groups,' Boessenecker said — 'offering unparalleled evolutionary insight.'
Prehistoric Dolphin Types
Abstract: Modern whales and dolphins are superbly adapted for marine life, with tail flukes being a key innovation shared by all extant species. Some dolphins can exceed speeds of 50 km/h, a feat accomplished by thrusting the flukes while adjusting attack angle with their flippers . These movements are driven by robust axial musculature anchored to a relatively rigid torso consisting of numerous short vertebrae, and controlled by hydrofoil-like flippers [2–7]. Eocene skeletons of whales illustrate the transition from semiaquatic to aquatic locomotion, including development of a fusiform body and reduction of hindlimbs [8–11], but the rarity of Oligocene whale skeletons [12, 13] has hampered efforts to understand the evolution of fluke-powered, but forelimb-controlled, locomotion. We report a nearly complete skeleton of the extinct large dolphin Ankylorhiza tiedemani comb. n. from the Oligocene of South Carolina, previously known only from a partial rostrum. Its forelimb is intermediate in morphology between stem cetaceans and extant taxa, whereas its axial skeleton displays incipient rigidity at the base of the tail with a flexible lumbar region. The position of Ankylorhiza near the base of the odontocete radiation implies that several postcranial specializations of extant cetaceans, including a shortened humerus, narrow peduncle, and loss of radial tuberosity, evolved convergently in odontocetes and mysticetes. Craniodental morphology, tooth wear, torso vertebral morphology, and body size all suggest that Ankylorhiza was a macrophagous predator that could swim relatively fast, indicating that it was one of the few extinct cetaceans to occupy a niche similar to that of killer whales.