A listing of prehistoric sea creatures that inhabited the world’s oceans earlier than, throughout, and after the age of the dinosaurs. Learn on to find superb prehistoric ocean animals akin to plesiosaurs, ichthyosaurs, pliosaurs, mosasaurs and ammonites.
Index
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Introduction
Dinosaurs stands out as the best-known prehistoric animals, however regardless of dominating the land in the course of the Mesozoic Period, they by no means tailored to life within the ocean.
Go to our important dinosaur web page to find every little thing you ever needed to find out about dinosaurs: Dinosaurs – The Full Information
So-called “sea-dinosaurs” akin to plesiosaurs and mosasaurs might have been reptiles, however they had been not dinosaurs, every forming their very own, separate department within the reptile household tree.
Beneath is a listing of prehistoric ocean animals from earlier than, throughout and after the Mesozoic Period. Many of the animals on the listing are reptiles, however different notable prehistoric sea creatures, together with fish and mammals, have additionally been included…
Ammonite
- Class of animal: Cephalopoda
- Household: Ammonoidea
- When it lived: Devonian to Cretaceous (roughly 400 to 66 million years in the past)
- The place discovered: Worldwide (fossils have been discovered on each continent)
- Measurement: Ranged from a number of centimeters / inches to over 2 meters / 6.5 ft. in diameter
Ammonites had been marine mollusks with spiral shells divided into chambers. Ammonites had been cephalopods, and as such, associated to fashionable squids, octopuses, and cuttlefish.
These free-swimming predators preyed on smaller marine creatures, and will have been in a position to squirt ink at potential predators, similar to fashionable cephalopods. Their extinction coincided with the mass extinction occasion that additionally worn out the dinosaurs.
Considerable in prehistoric oceans, ammonites are used as index fossils – their widespread presence and speedy evolution permit geologists to precisely date and correlate rock layers throughout completely different geographic areas.
You could find out extra about ammonites on this web page: Ammonite Info
Archelon
- Class of animal: Reptilia (Turtle)
- Household: Protostegidae
- When it lived: Late Cretaceous (about 80 to 74 million years in the past)
- The place discovered: North America (fossils primarily discovered within the Western Inside Seaway)
- Measurement: As much as 4.6 meters (15 ft) in size and about 3.3 meters (11 ft) flipper span
The most important turtle ever recognized, Archelon was longer than the mixed peak of two males.
This prehistoric sea turtle had a leathery carapace – much like that of the dwelling leatherback turtle – fairly than a tough shell, and elongated, paddle-like flippers for swimming. Regardless of similarities between the 2, Archelon was not associated to the leatherback sea turtle.
The massive dimension and highly effective flippers of Archelon made it a powerful swimmer, enabling it emigrate over lengthy distances within the ocean. It had highly effective jaws for crushing prey, and certain consumed mollusks, crustaceans, and jellyfish.
Basilosaurus
- Class of animal: Mammalia (Cetacean)
- Household: Basilosauridae
- When it lived: Late Eocene (about 41 to 33.9 million years in the past)
- The place discovered: North America, Northern Africa, West Asia
- Measurement: Roughly 15 to twenty meters (49 to 66 ft) in size
Basilosaurus was an early whale with an extended, slender physique resembling that of a snake or eel.
Regardless of having “saurus” as a part of its title (saurus comes from the Greek for “Lizard” and often denotes a reptile), Basilosaurus, like all whales, was a mammal. (On the time of its naming, this huge prehistoric sea creature was thought to have been a reptile.)
Basilosaurus was probably a high predator in its marine surroundings, feeding on fish, sharks, and presumably different marine mammals. Its elongated physique and huge dimension made it a formidable hunter.
Cretoxyrhina
- Class of animal: Chondrichthyes (Shark)
- Household: Cretoxyrhinidae
- When it lived: Late Cretaceous (about 100 to 82 million years in the past)
- The place discovered: Worldwide (fossils present in North America, Europe, and Africa)
- Measurement: As much as 8 meters (26 ft) in size
Cretoxyrhina was a big shark from the Cretaceous Interval. Like dwelling sharks, it has a sturdy physique, highly effective jaws, and sharp, serrated tooth designed for slicing by means of flesh.
This prehistoric shark was found in East Sussex, England, by paleontologist Gideon Mantell. It was later given the title Cretoxyrhina mantelli in honor of the scientist. The species is often known as the Ginsu shark.
Cretoxyrhina was an apex predator in its ecosystem, preying on quite a lot of marine animals, together with fish, different sharks, and marine reptiles. Its fossilized tooth and vertebrae are present in Late Cretaceous marine deposits.
Dakosaurus
- Class of animal: Reptilia (Crocodylomorpha – a gaggle that comprises crocodiles and associated animals)
- Household: Metriorhynchidae
- When it lived: Late Jurassic to Early Cretaceous (about 157 to 137 million years in the past)
- The place discovered: Europe and South America
- Measurement: As much as 5 meters (16 ft) in size
Dakosaurus was a marine crocodyliform with a sturdy physique, elongated jaws, and serrated tooth resembling these of theropod dinosaurs.
Not like fashionable crocodiles, Dakosaurus was absolutely tailored to marine life with paddle-like limbs and a tail fluke for swimming. Scientists are uncertain whether or not it laid eggs on land like at this time’s sea turtles, or carried out its total life cycle at sea.
With its highly effective jaws, Dakosaurus was most likely a high predator in its oceanic surroundings, searching fish and different marine reptiles. Its fearsome look has earned it the nickname “Godzilla”.
Dunkleosteus
- Class of animal: Placodermi (an extinct group of prehistoric fish)
- Household: Dunkleosteidae
- When it lived: Late Devonian (about 382 to 358 million years in the past)
- The place discovered: North America, Europe, and Morocco
- Measurement: As much as 10 meters (33 ft) in size
Dunkleosteus was one of many largest and most fearsome prehistoric fish, with a closely armored head and thorax. Its jaws had been outfitted with sharp, bony plates that acted like shears, able to slicing by means of the hardest prey.
This fearsome prehistoric fish is believed to have had one of many strongest chew forces of any recognized animal. Estimates of the utmost size of Dunkleosteus vary from round 5 m / 16.5 ft to as much as 10 m / 33 ft.
Dunkleosteus lived in the course of the Devonian Interval, tens of millions of years earlier than the arrival of the dinosaurs.
Probably an apex predator in its marine surroundings, Dunkleosteus consumed different fish and marine animals. Its highly effective chew and big dimension would have made it a dominant power within the Devonian seas.
Elasmosaurus
- Class of animal: Reptilia (Plesiosaur)
- Household: Elasmosauridae
- When it lived: Late Cretaceous (about 80.5 million years in the past)
- The place discovered: North America (notably within the Western Inside Seaway)
- Measurement: As much as 14 meters (46 ft) in size, with the neck alone being about 7 meters (23 ft) lengthy
Elasmosaurus was a long-necked marine reptile recognized for its highly-elongated neck, which made up almost half of its whole physique size. It, and the associated Albertonectes, are the longest-necked animals that ever lived.
Like different long-necked plesiosaurs, Elasmosaurus had a small head, giant flippers, and a streamlined physique, tailored for swimming. It probably consumed small fish and invertebrates, utilizing its elongated neck to comb by means of faculties of fish or to ambush prey.
Helicoprion
- Class of animal: Chondrichthyes (Cartilaginous fish)
- Household: Helicoprionidae
- When it lived: Early Mid-Permian Interval (about 290 to 270 million years in the past)
- The place discovered: Worldwide (fossils primarily present in North America, Japanese Europe, Asia, and Australia)
- Measurement: Estimated as much as 8 meters (26 ft) in size
Helicoprion was a cartilaginous fish recognized for its distinctive spiral jaw, which housed a whorl of serrated tooth. This “tooth-whorl” was situated within the decrease jaw and certain functioned to slice and crush its prey, which included soft-bodied animals akin to cephalopods.
With a torpedo-like physique and huge, forked tail, Helicoprion was probably a fast-moving predator of the open oceans.
Ichthyosaurs
- Class of animal: Reptilia
- Household: Ichthyosauridae (and different associated households inside Ichthyosauria)
- When it lived: Early Triassic to Late Cretaceous (about 250 to 90 million years in the past)
- The place discovered: Worldwide (fossils present in North America, Europe, Asia, and Australia)
- Measurement: Ranged from below 1 meter (3 ft) to over 20 meters (66 ft) in size, relying on the species
Ichthyosaurs had been a gaggle (the order Ichthyosauria) of marine reptiles that resembled fashionable dolphins and fish, with streamlined our bodies, elongated snouts, and huge eyes. They had been extremely tailored to life within the ocean, possessing robust, paddle-like limbs and tails for environment friendly swimming.
The title “Ichthyosaurs” means “fish lizard”. The resemblance of Ichthyosaurs to dwelling fish and dolphins is an instance of convergent evolution – the phenomenon of unrelated animals creating related traits.
Ichthyosaurs had been probably high predators, feeding on fish, squid, and different marine organisms. They’re recognized for giving dwell beginning, as evidenced by fossilized stays of pregnant people.
Top-of-the-line-known ichthyosaurs was Ichthyosaurus (see under), which lived in the course of the Early Jurassic. Ichthyosaurus went extinct within the Jurassic Interval, however different kinds of ichthyosaurs lived virtually to the top of the Cretaceous Interval.
Ichthyosaurus
- Class of animal: Reptilia (Ichthyosaur)
- Household: Ichthyosauridae
- When it lived: Early Jurassic (about 200 to 190 million years in the past)
- The place discovered: Europe (notably in England and Germany)
- Measurement: Round to three meters (10 ft) in size
Ichthyosaurus was a genus of ichthyosaur that had a fish-like physique, giant eyes, and an extended, pointed snout stuffed with conical tooth. It was an agile swimmer, well-adapted to searching fish and squid within the early Jurassic seas. Its giant eyes counsel it had good imaginative and prescient, presumably for searching in low-light situations.
Fossil proof reveals that Ichthyosaurus gave beginning to dwell younger, with some specimens preserving embryos throughout the physique. The genus is without doubt one of the best-known and most studied ichthyosaurs.
Livyatan melvillei
- Class of animal: Mammalia (Cetacean)
- Household: Physeteroidea
- When it lived: Late Miocene to Early Pliocene (about 10 to five million years in the past)
- The place discovered: South America (notably in Peru)
- Measurement: Estimated as much as 17.5 meters (57 ft) in size
Livyatan melvillei was an enormous prehistoric sperm whale with huge tooth measuring as much as 36 cm (14 inches) in size. Not like fashionable sperm whales, which have tooth solely of their decrease jaws, Livyatan had tooth in each higher and decrease jaws, suggesting it was an energetic predator.
This prehistoric marine predator probably hunted giant prey, together with different marine mammals akin to seals and smaller whales. Its huge dimension and formidable dentition made it one of many high predators within the Miocene oceans, much like the fashionable orca by way of ecological position.
The second a part of the species’ scientific title, melvillei, honors the writer Herman Melville, author of “Moby Dick”, a novel that includes an enormous sperm whale.
Liopleurodon
- Class of animal: Reptilia (Pliosaur)
- Household: Pliosauridae
- When it lived: Center to Late Jurassic (about 166 to 155 million years in the past)
- The place discovered: Europe (notably in England and France)
- Measurement: As much as 6.4 meters (21 ft) in size (some estimates counsel as much as 10 meters / 33 ft)
The household Pliosauridae contained each long-necked and short-necked, large-headed species. The short-necked group is known as Thalassophonea, and one among its best-known members is Liopleurodon.
Liopleurodon was a big pliosaur outfitted with highly effective jaws, with which it hunted giant prey, together with fish, squid, and different marine reptiles. It had a sturdy physique with robust, paddle-like limbs that offered the swift acceleration required for an ambush predator.
This Jurassic apex predator probably had a well-developed sense of odor, as indicated by its giant nasal openings, which might have helped it detect prey from a distance.
Megalodon
- Class of animal: Chondrichthyes (Cartilaginous fish)
- Household: Otodontidae
- When it lived: Early Miocene to Pliocene (about 23 to three.6 million years in the past)
- The place discovered: Worldwide (fossils discovered on each continent besides Antarctica)
- Measurement: Estimates vary from 15 to 18 meters (49 to 59 ft) in size
Otodus megalodon, often recognized merely as Megalodon, is believed to have been the most important shark that ever lived.
Resembling a dwelling shark, however bigger, Megalodon had huge, serrated tooth measuring as much as 18 cm (7 inches) in size. With a tremendously highly effective chew power – presumably the best of any animal alive or extinct, even the shells of sea turtles would have posed no issue to Megalodon. Additionally on the menu would have been whales, seals, and sea turtles.
Megalodon inhabited heat, coastal waters around the globe. Megalodons went extinct round a million years earlier than the arrival of Homo habilis, an early ancestor of people.
You could find out extra about Megalodon on this web page: Megalodon Info
Mosasaurs
- Class of animal: Reptilia
- Household: Mosasauridae
- When it lived: Late Cretaceous (about 98 to 66 million years in the past)
- The place discovered: Worldwide (fossils present in North America, Europe, Africa, South America, and Asia)
- Measurement: Ranged from 1 meter (3.3 ft) to over 17 meters (56 ft) in size, relying on the species
Following the extinction of the ichthyosaurs and pliosaurs, it was the flip of the Mosasaurs to dominate the oceans of the Late Cretaceous. These giant, predatory marine reptiles belong to the reptile group Squamata, which can also be dwelling to lizards and snakes. They’re thought to have advanced from small, coastal lizards, and could also be associated to observe lizards.
A scientific examine printed in 2016 suggests Mosasaurs had forked tongues. (supply)
The robust jaws of mosasaurs had been lined with sharp tooth, enabling them to hunt all kinds of prey, together with fish, sharks, cephalopods, and even different marine reptiles. Their anatomy suggests they had been quick and agile swimmers, able to ambushing or pursuing their prey.
Mosasaurs are thought of one of many high marine predators of their time, and their widespread fossil distribution highlights their success and flexibility in historical marine ecosystems.
You could find out extra about mosasaurs on this web page: Mosasaur Info
Mosasaurus
- Class of animal: Reptilia (Mosasaur)
- Household: Mosasauridae
- When it lived: Late Cretaceous (about 80 to 66 million years in the past)
- The place discovered: Worldwide (notably in North America and Europe)
- Measurement: As much as 17 meters (56 ft) in size
Mosasaurus was one of many largest and most formidable mosasaurs, possessing a sturdy physique, an extended, highly effective tail, and paddle-like limbs tailored for environment friendly swimming. It had an elongated head with robust jaws lined with quite a few sharp tooth, designed for gripping and tearing prey.
Mosasaurus was an apex predator in its marine surroundings, preying on quite a lot of marine animals, together with fish, sharks, cephalopods, and smaller marine reptiles. Its highly effective construct and predatory abilities made it a dominant power within the Late Cretaceous oceans.
You could find out extra about mosasaurus on this web page: Mosasaurus Info
Nothosaurs
- Class of animal: Reptilia
- Household: Nothosauridae
- When it lived: Center Triassic to Late Triassic (about 240 to 210 million years in the past)
- The place discovered: Europe, Asia, and North Africa
- Measurement: Ranged from 3 to 4 meters (10 to 13 ft) in size
Nothosaurs had been semi-aquatic reptiles with elongated our bodies, lengthy necks, and limbs tailored for each swimming and strolling on land. They’d webbed ft and a streamlined form that allowed for environment friendly motion in water, however they may additionally transfer on land, much like fashionable seals.
Nothosaurs had elongated jaws stuffed with sharp tooth, supreme for catching fish and different small marine animals. Their twin way of life and flexibility made them profitable predators in each marine and coastal environments in the course of the Triassic interval.
Nothosaurus
- Class of animal: Reptilia (Nothosaur)
- Household: Nothosauridae
- When it lived: Center Triassic to Late Triassic (about 240 to 210 million years in the past)
- The place discovered: Europe and Asia
- Measurement: Round 4 meters (13 ft) in size
Nothosaurus is the best-known sort of nothosaur. This semi-aquatic Triassic predator had a streamlined physique, lengthy neck, and webbed limbs, and was semi-aquatic, having the ability to transfer each within the water and on land.
The elongated, crocodile-like jaws of Nothosaurus had been stuffed with sharp, conical tooth, appropriate for catching slippery prey akin to fish and squid.
Nothosaurus had a life-style much like that of contemporary seals, being able to swimming effectively in water whereas additionally having the ability to haul out onto land. Their fossils are sometimes present in marine deposits, indicating that they spent a major period of time within the water, however additionally they probably basked and nested on land.
Opabinia
- Class of animal: Marrellomorpha (usually debated) (Arthropod)
- Household: Opabiniidae
- When it lived: Center Cambrian (about 505 million years in the past)
- The place discovered: North America (notably within the Burgess Shale, Canada)
- Measurement: Roughly 7 centimeters (2.8 inches) in size
One of many earliest animals on this listing of prehistoric ocean creatures, Opabinia was a marine arthropod that lived over 500 million years in the past.
This small, soft-bodied marine animal is notable for its uncommon look, with 5 eyes on stalks and an extended, versatile proboscis with a claw-like construction on the finish. This proboscis was probably used to know and manipulate meals.
The physique of Opabinia had lobes alongside its sides and a fan-shaped tail, suggesting it was a swimmer that moved by means of the water by undulating its physique and lobes. Its distinctive anatomy has made it some of the intriguing and iconic creatures from the Cambrian interval.
Plesiosaurs
- Class of animal: Reptilia
- Household: Plesiosauridae (and different associated households inside Plesiosauria)
- When it lived: Late Triassic to Late Cretaceous (about 203 to 66 million years in the past)
- The place discovered: Worldwide (fossils found on each continent)
- Measurement: Ranged from 2 to fifteen meters (6.5 to 49 ft) in size, relying on the species
Plesiosaurs had been giant marine reptiles with broad our bodies, brief tails, and 4 lengthy, paddle-like limbs that they used for propulsion in water. They had been some of the profitable teams of prehistoric sea animals, dwelling from the Late Triassic all the way in which as much as the extinction occasion on the finish of the Cretaceous Interval during which the dinosaurs additionally turned extinct.
There have been two important teams of plesiosaurs: long-necked (plesiosauromorphs) and short-necked (pliosauromorphs). The long-necked plesiosaurs had elongated necks and small heads, which they probably used to catch small fish and different marine organisms.
The short-necked varieties had bigger heads and highly effective jaws, tailored for searching bigger prey.
Plesiosaurus
- Class of animal: Reptilia (Plesiosaur)
- Household: Plesiosauridae
- When it lived: Early Jurassic (about 201 to 183 million years in the past)
- The place discovered: Europe (notably in England and Germany)
- Measurement: Roughly 3.5 to 4.5 meters (11 to fifteen ft) in size
Plesiosaurus was a long-necked plesiosaur with a broad, flat physique, a brief tail, and 4 giant, paddle-like limbs used for swimming. Its lengthy, versatile neck and small head with sharp tooth had been supreme variations for catching fish and different small marine creatures.
One principle on how Plesiosaurus moved by means of the water means that it used its 4 flippers in a coordinated method much like underwater “flying”. One other, earlier, principle proposes that each one 4 flippers labored in a extra synchronized, rowing-like movement to propel the massive sea creature effectively by means of the water.
Plesiosaurus was the primary plesiosaur to be found.
Pliosaurs
- Class of animal: Reptilia
- Household: Pliosauridae
- When it lived: Early Jurassic to Late Cretaceous (about 201 to 80 million years in the past)
- The place discovered: Worldwide (fossils present in North America, Europe, South America, and Australia)
- Measurement: Ranged from 4 to fifteen meters (13 to 49 ft) in size, relying on the species
Pliosaurs had been a gaggle of plesiosaurs with brief necks, giant heads, highly effective jaws stuffed with sharp tooth, and strong our bodies. The hind flippers of pliosaurs had been longer than the fore-flippers (in different kinds of plesiosaurs, the other is true).
These prehistoric ocean reptiles had been formidable predators, able to searching giant prey, together with fish, squid, and different marine reptiles.
Two well-known examples of pliosaurs are Liopleurodon and Kronosaurus, each famend for his or her giant dimension and highly effective jaws.
Pliosaurus
- Class of animal: Reptilia (Pliosaur)
- Household: Pliosauridae
- When it lived: Late Jurassic (about 155 to 145 million years in the past)
- The place discovered: Europe (notably in England and France), with attainable stays present in South America and Australia
- Measurement: Estimated as much as 10 to 13 meters (33 to 43 ft) in size
Pliosaurus was a genus of enormous, predatory marine reptiles characterised by a sturdy physique, comparatively brief neck, and an infinite head outfitted with highly effective jaws and huge, conical tooth.
On the time of writing, six species of Pliosaurus are acknowledged. The primary species to be named was Pliosaurus brachydeirus. It was named by English paleontologist Richard Owen, who additionally invented the time period “dinosaur” to explain the now-famous group of prehistoric land animals.
Shastasaurus
- Class of animal: Reptilia (Ichthyosaur)
- Household: Shastasauridae
- When it lived: Late Triassic (about 215 to 210 million years in the past)
- The place discovered: North America (notably in California and Nevada), with attainable stays in China
- Measurement: Estimated as much as 10 meters (33 ft) in size
Shastasaurus was one of many largest recognized ichthyosaurs, with a streamlined, dolphin-like physique tailored for environment friendly swimming within the open ocean.
Not like many different ichthyosaurs, Shastasaurus had a comparatively brief, blunt snout and lacked the standard elongated, conical tooth, suggesting it might have consumed soft-bodied prey like squid and fish utilizing suction feeding.
Its giant dimension and streamlined form point out that Shastasaurus was well-suited for deep diving and long-distance swimming.
Tylosaurus
- Class of animal: Reptilia (Mosasaur)
- Household: Mosasauridae
- When it lived: Late Cretaceous (about 85 to 66 million years in the past)
- The place discovered: North America (notably within the Western Inside Seaway)
- Measurement: As much as 14 meters (46 ft) in size
Tylosaurus was a big, predatory mosasaur with an extended, streamlined physique and highly effective, paddle-like limbs tailored for swimming. It had an elongated head with a particular, bony protrusion on its snout, and its jaws had been stuffed with sharp tooth, supreme for catching and holding onto prey.
Tylosaurus was an apex predator in its marine surroundings, preying on fish, sharks, smaller marine reptiles, and even seabirds. Its highly effective swimming skills and predatory abilities made it one of many dominant marine sea animals of the Late Cretaceous interval.
Xiphactinus
- Class of animal: Actinopterygii (Bony fish)
- Household: Ichthyodectidae
- When it lived: Late Cretaceous (about 112 to 66 million years in the past)
- The place discovered: North America, Europe, and Australia (notably within the Western Inside Seaway of North America)
- Measurement: As much as 6 meters (20 ft) in size
Xiphactinus was a big, predatory bony fish recognized for its strong physique, elongated, streamlined form, and huge, fang-like tooth. It had a powerful, upturned decrease jaw, which gave it a formidable look. Its physique form resembled that of a contemporary tarpon
Xiphactinus was an apex predator in its marine surroundings, able to quick swimming and certain ambushing or chasing down prey, which included smaller fish and different marine animals. A number of fossils of Xiphactinus have smaller fish preserved inside their stomachs.
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