Prehistoric Whale Pictures and Profiles

Meet the Ancestral Whales of the Cenozoic Era

Over the course of 50 million years, beginning in the early Eocene epoch, whales evolved from their tiny, terrestrial, four-legged progenitors to the giants of the sea they are today. On the following slides, you'll find pictures and detailed profiles of over 20 prehistoric whales, ranging from A (Acrophyseter) to Z (Zygorhiza).

Acrophyseter

Name:

Acrophyseter (Greek for "acute sperm whale"); pronounced ACK-roe-FIE-zet-er

Habitat:

Pacific Ocean

Historical Epoch:

Late Miocene (6 million years ago)

Size and Weight:

About 12 feet long and half a ton

Diet:

Fish, whales and birds

Distinguishing Characteristics:

Moderate size; long, pointed snout

You can gauge the measure of the prehistoric sperm whale Acrophyseter by its full name: Acrophyseter deinodon, which translates roughly as "pointy-snouted sperm whale with terrible teeth" ("terrible" in this context meaning scary, not rotten). This "killer sperm whale," as it's sometimes called, possessed a long, pointed snout studded with sharp teeth, making it look a bit like a cross between a cetacean and a shark. Unlike modern sperm whales, which feed mostly on squids and fish, Acrophyseter seems to have pursued a more varied diet, including sharks, seals, penguins and even other prehistoric whales. As you can guess from its name, Acrophyseter was closely related to another sperm whale ancestor, Brygmophyseter.

Aegyptocetus

Name

Aegyptocetus (Greek for "Egyptian whale"); pronounced ay-JIP-toe-SEE-tuss

Habitat

Shores of northern Africa

Historical Epoch

Late Eocene (40 million years ago)

Size and Weight

Undisclosed

Diet

Marine organisms

Distinguishing Characteristics

Bulky, walrus-like body; webbed feet

One doesn't normally associate Egypt with whales, but the fact is that the fossils of prehistoric cetaceans have turned up in some very unlikely (from our perspective) locations. To judge by its partial remains, which were recently discovered in the Wadi Tarfa region of the eastern Egyptian desert, Aegyptocetus occupied a niche midway between its landbound ancestors of the earlier Cenozoic Era (such as Pakicetus) and the fully aquatic whales, like Dorudon, that evolved a few million years later. Specifically, Aegyptocetus' bulky, walrus-like torso doesn't exactly scream "hydrodynamic," and its long front legs indicate that it spent at least part of its time on dry land.

Aetiocetus

Name:

Aetiocetus (Greek for "original whale"); pronounced AY-tee-oh-SEE-tuss

Habitat:

Pacific coast of North America

Historical Epoch:

Late Oligocene (25 million years ago)

Size and Weight:

About 25 feet long and a few tons

Diet:

Fish, crustaceans and plankton

Distinguishing Characteristics:

Both teeth and baleen in jaws

The importance of Aetiocetus lies in its feeding habits: this 25-million-year-old prehistoric whale had baleen alongside the fully developed teeth in its skull, leading paleontologists to infer that it fed mostly on fish but also filtered the occasional smaller crustaceans and plankton from the water. Aetiocetus appears to have been an intermediate form between the earlier, land-bound whale ancestor Pakicetus and contemporary gray whales, which dine exclusively on baleen-filtered plankton.

Ambulocetus

How do paleontologists know that Ambulocetus was ancestral to modern whales? Well, for one thing, the bones in this mammal's ears were similar to those of modern cetaceans, as were its whale-like teeth and its ability to swallow underwater. See an in-depth profile of Ambulocetus

Basilosaurus

Basilosaurus was one of the largest mammals of the Eocene epoch, rivaling the bulk of earlier, terrestrial dinosaurs. Because it had such small flippers relative to its size, this prehistoric whale probably swam by undulating its long, snake-like body. See 10 Facts About Basilosaurus

Brygmophyseter

Name:

Brygmophyseter (Greek for "biting sperm whale"); pronounced BRIG-moe-FIE-zet-er

Habitat:

Pacific Ocean

Historical Epoch:

Miocene (15-5 million years ago)

Size and Weight:

Up to 40 feet long and 5-10 tons

Diet:

Sharks, seals, birds and whales

Distinguishing Characteristics:

Large size; long, toothed snout

Not the most euphoniously named of all prehistoric whales, Brygmophyseter owes its place in the pop-culture spotlight to the defunct TV series Jurassic Fight Club, an episode of which pitted this ancient sperm whale against the giant shark Megalodon. We'll never know if a battle like this ever took place, but clearly Brygmophyseter would have put up a good fight, considering its large size and tooth-studded snout (unlike modern sperm whales, which feed on easily digestible fish and squids, Brygmophyseter was an opportunistic predator, chomping down on penguins, sharks, seals and even other prehistoric whales). As you can guess from its name, Brygmophyeter was closely related to another "killer sperm whale" of the Miocene epoch, Acrophyseter.

Cetotherium

Name:

Cetotherium (Greek for "whale beast"); pronounced SEE-toe-THEE-ree-um

Habitat:

Seashores of Eurasia

Historical Epoch:

Middle Miocene (15-10 million years ago)

Size and Weight:

About 15 feet long and one ton

Diet:

Plankton

Distinguishing Characteristics:

Small size, short baleen plates

For all intents and purposes, the prehistoric whale Cetotherium can be considered a smaller, sleeker version of the modern gray whale, about one-third the length of its famous descendant and presumably much harder to spot from a long distance away. Like the gray whale, Cetotherium filtered plankton from seawater with baleen plates (which were relatively short and underdeveloped), and it was likely preyed on by the giant, prehistoric sharks of the Miocene epoch, possibly including the gigantic Megalodon.

Cotylocara

The prehistoric whale Cotylocara had a deep cavity in the top of its skull surrounded by a reflecting "dish" of bone, ideal for funneling tightly focused blasts of air; scientists believe it may have been one of the earliest cetaceans with the ability to echolocate. See an in-depth profile of Cotylocara

Dorudon

The discovery of juvenile Dorudon fossils finally convinced paleontologists that this short, stubby cetacean merited its own genus--and may actually have been preyed on by the occasional hungry Basilosaurus, for which it was once mistaken. See an in-depth profile of Dorudon

Georgiacetus

One of the most common fossil whales of North America, the remains of the four-legged Georgiacetus have been unearthed not only in the state of Georgia, but in Mississippi, Alabama, Texas and South Carolina as well. See an in-depth profile of Georgiacetus

Indohyus

Name:

Indohyus (Greek for "Indian pig"); pronounced IN-doe-HIGH-us

Habitat:

Shores of central Asia

Historical Epoch:

Early Eocene (48 million years ago)

Size and Weight:

About two feet long and 10 pounds

Diet:

Plants

Distinguishing Characteristics:

Small size; thick hide; herbivorous diet

About 55 million years ago, at the start of the Eocene epoch, a branch of artiodactyls (the even-toed mammals represented today by pigs and deer) slowly veered off onto the evolutionary line that slowly led to modern whales. The ancient artiodactyl Indohyus is important because (at least according to some paleontologists) it belonged to a sister group of these earliest prehistoric cetaceans, closely related to genera like Pakicetus, which lived a few million years earlier. Although it doesn't occupy a place on the direct line of whale evolution, Indohyus displayed characteristic adaptations to a marine environment, most notably its thick, hippopotamus-like coat.

Janjucetus

Name:

Janjucetus (Greek for "Jan Juc whale"); pronounced JAN-joo-SEE-tuss

Habitat:

Southern coast of Australia

Historical Period:

Late Oligocene (25 million years ago)

Size and Weight:

About 12 feet long and 500-1,000 pounds

Diet:

Fish

Distinguishing Characteristics:

Dolphin-like body; large, sharp teeth

Like its close contemporary Mammalodon, the prehistoric whale Janjucetus was ancestral to modern blue whales, which filter plankton and krill through baleen plates--and also like Mammalodon, Janjucetus possessed unusually large, sharp, and well-separated teeth. That's where the similarities end, though--whereas Mammalodon may have used its blunt snout and teeth to rustle up small marine creatures from the sea floor (a theory that hasn't been accepted by all paleontologists), Janjucetus seems to have behaved more like a shark, pursuing and eating larger fish. By the way, the fossil of Janjucetus was discovered in southern Australia by a teenage surfer; this prehistoric whale can thank the nearby township of Jan Juc for its unusual name.

Kentriodon

Name

Kentriodon (Greek for "spiky tooth"); pronounced ken-TRY-oh-don

Habitat

Coasts of North America, Eurasia and Australia

Historical Epoch

Late Oligocene-Middle Miocene (30-15 million years ago)

Size and Weight

About 6 to 12 feet long and 200-500 pounds

Diet

Fish

Distinguishing Characteristics

Moderate size; dolphin-like snout and blowhole

We simultaneously know a lot, and very little, about the ultimate ancestors of the Bottlenose Dolphin. On the one hand, there are at least a dozen identified genera of "kentriodontids" (toothed prehistoric whales with dolphin-like features), but on the other hand, many of these genera are poorly understood and based on fragmentary fossil remains. That's where Kentriodon comes in: this genus persisted worldwide for a whopping 15 million years, from the late Oligocene to the middle Miocene epochs,, and the dolphin-like position of its blowhole (combined with its presumed ability to echolocate and swim in pods) make it the best-attested Bottlenose ancestor.

Kutchicetus

Name:

Kutchicetus (Greek for "Kachchh whale"); pronounced KOO-chee-SEE-tuss

Habitat:

Shores of central Asia

Historical Epoch:

Middle Eocene (46-43 million years ago)

Size and Weight:

About eight feet long and a few hundred pounds

Diet:

Fish and squids

Distinguishing Characteristics:

Small size; unusually long tail

Modern India and Pakistan have proven a rich source of prehistoric whale fossils, having been submerged under water for much of the Cenozoic Era. Among the latest discoveries on the subcontinent is the middle Eocene Kutchicetus, which was clearly built for an amphibious lifestyle, able to walk on land yet also using its unusually long tail to propel itself through the water. Kutchicetus was closely related to another (and more famous) whale precursor, the more evocatively named Ambulocetus ("walking whale").

Leviathan

The 10-foot-long, tooth-studded skull of Leviathan (full name: Leviathan melvillei, after the author of Moby Dick) was discovered off the coast of Peru in 2008, and it hints at a merciless, 50-foot-long predator that likely feasted on smaller whales. See 10 Facts About Leviathan

Maiacetus

Name:

Maiacetus (Greek for "good mother whale"); pronounced MY-ah-SEE-tuss

Habitat:

Shores of central Asia

Historical Epoch:

Early Eocene (48 million years ago)

Size and Weight:

About seven feet long and 600 pounds

Diet:

Fish and squids

Distinguishing Characteristics:

Medium size; amphibious lifestyle

Discovered in Pakistan in 2004, Maiacetus ("good mother whale") shouldn't be confused with the more famous duck-billed dinosaur Maiasaura. This prehistoric whale earned its name because the fossil of an adult female was found to contain a fossilized embryo, the positioning of which hints that this genus lumbered onto land to give birth. Researchers have also discovered the near-complete fossil of a male Maiacetus adult, the larger size of which is evidence for early sexual dimorphism in whales.

Mammalodon

Mammalodon was a "dwarf" ancestor of the modern Blue Whale, which filters plankton and krill using baleen plates--but it's unclear whether Mammalodon's odd tooth structure was a one-shot deal, or represented an intermediate step in whale evolution. See an in-depth profile of Mammalodon

Pakicetus

The early Eocene Pakicetus may have been the earliest whale ancestor, a mostly terrestrial, four-footed mammal that ventured occasionally into the water to nab fish (its ears, for example, weren't adapted to hearing well underwater). See an in-depth profile of Pakicetus

Protocetus

Name:

Protocetus (Greek for "first whale"); pronounced PRO-toe-SEE-tuss

Habitat:

Shores of Africa and Asia

Historical Epoch:

Middle Eocene (42-38 million years ago)

Size and Weight:

About eight feet long and a few hundred pounds

Diet:

Fish and squids

Distinguishing Characteristics:

Small size; seal-like body

Despite its name, Protocetus wasn't technically the "first whale;" as far as we know, that honor belongs to the four-legged, land-bound Pakicetus, which lived a few million years earlier. Whereas the dog-like Pakicetus ventured only occasionally into the water, Protocetus was much better adapted to an aquatic lifestyle, with a lithe, seal-like body and powerful front legs (already well on their way to becoming flippers). Also, the nostrils of this prehistoric whale were located midway up its forehead, foreshadowing the blowholes of its modern descendants, and its ears were better adapted to hearing underwater.

Remingtonocetus

Name

Remingtonocetus (Greek for "Remington's whale"); pronounced REH-mng-ton-oh-SEE-tuss

Habitat

Shores of southern Asia

Historical Epoch

Eocene (48-37 million years ago)

Size and Weight

Undisclosed

Diet

Fish and marine organisms

Distinguishing Characteristics

Long, slender body; narrow snout

Modern-day India and Pakistan aren't exactly hotbeds of fossil discovery--which is why it's so strange that so many prehistoric whales have been unearthed on the subcontinent, especially those sporting terrestrial legs (or at least legs recently adapted to a terrestrial habitat). Compared to standard-bearing whale ancestors like Pakicetus, not much is known about Remingtonocetus, except for the fact that it had an unusually slender build and seems to have used its legs (rather than its torso) to propel itself through the water.

Rodhocetus

Rodhocetus was a large, streamlined prehistoric whale of the early Eocene epoch that spent most of its time in the water--though its splay-footed posture demonstrates that it was capable of walking, or rather dragging itself along on, dry land. See an in-depth profile of Rodhocetus

Squalodon

Name

Squalodon (Greek for "shark tooth"); pronounced SKWAL-oh-don

Habitat

Oceans worldwide

Historical Epoch

Oligocene-Miocene (33-14 million years ago)

Size and Weight

Undisclosed

Diet

Marine animals

Distinguishing Characteristics

Narrow snout; short neck; complex shape and arrangement of teeth

In the early 19th century, not only were random dinosaurs likely to be assigned as species of Iguanodon; the same fate also befell prehistoric mammals. Diagnosed in 1840 by a French paleontologist, based on scattered segments of a single jaw, Squalodon was misunderstood not once, but twice: not only was it first identified as a plant-eating dinosaur, but its name is Greek for "shark tooth," meaning it took a while for experts to realize that they were actually dealing with a prehistoric whale.

Even after all these years, Squalodon remains a mysterious beast--which can (at least partly) be attributed to the fact that no complete fossil has ever been found. In general terms, this whale was intermediate between earlier "archaeocetes" like Basilosaurus and modern genera like orcas (aka Killer Whales). Certainly, the dental details of Squalodon were more primitive (witness the sharp, triangular cheek teeth) and haphazardly arranged (the tooth spacing is more generous than is seen in modern toothed whales), and there are hints that it had a rudimentary ability to echolocate. We don't know exactly why Squalodon (and other whales like it) disappeared during the Miocene epoch, 14 million years ago, but it may have had something to do with climate change and/or the advent of better-adapted dolphins.

Zygorhiza

Name:

Zygorhiza (Greek for "yoke root"); pronounced ZIE-go-RYE-za

Habitat:

Shores of North America

Historical Epoch:

Late Eocene (40-35 million years ago)

Size and Weight:

About 20 feet long and one ton

Diet:

Fish and squids

Distinguishing Characteristics:

Long, narrow body; long head

About Zygorhiza

Like its fellow prehistoric whale Dorudon, Zygorhiza was closely related to the monstrous Basilosaurus, but differed from both of its cetacean cousins in that it had an unusually sleek, narrow body and a long head perched on a short neck. Strangest of all, Zygorhiza's front flippers were hinged at the elbows, a hint that this prehistoric whale may have lumbered up onto land to give birth to its young. By the way, along with Basilosaurus, Zygorhiza is the state fossil of Mississippi; the skeleton at the Mississippi Museum of Natural Science is affectionately known as "Ziggy."

Zygorhiza differed from other prehistoric whales in that it had an unusually sleek, narrow body and a long head perched on a short neck. Its front flippers were hinged at the elbow, a hint that Zygorhiza may have lumbered onto land to give birth to its young.