Life in ancient oceans

04Paleozoic

They occupied seafloors for nearly 300 million years, and their compound eyes preserve secrets of early vision.

14Mesozoic

A giant marine lizard propelled by a deep tail fin patrolled Late Cretaceous seas.

15Paleozoic

Sharpened jaw plates replaced teeth in this heavily armored apex fish.

16Cenozoic

Its hand-sized teeth belonged to a giant shark specialized in hunting marine mammals.

27Recently extinct

This enormous, slow sirenian grazed kelp in cold shallow water.

30Paleozoic

A meter-long swimmer with grasping frontal appendages was a giant of Cambrian seas.

31Paleozoic

Five eyes and a grasping proboscis made this small swimmer one of the Cambrian’s strangest forms.

32Paleozoic

Paired spines guarded a soft-bodied walker once reconstructed upside down.

34Paleozoic

A long straight shell housed one of the largest predators of Ordovician seas.

35Paleozoic

Its spiral tooth whorl worked like a permanent slicing blade inside the lower jaw.

36Paleozoic

Opposing tooth blades projected from its jaws like curved shears.

56Mesozoic

Long wings and a toothless beak carried this pterosaur over an inland sea.

57Mesozoic

An extraordinarily long neck let this marine reptile approach prey with a small head.

58Mesozoic

A streamlined reptile converged on the body plan of dolphins while retaining enormous eyes.

59Mesozoic

A broad skull and four powerful flippers belonged to a leading Jurassic marine predator.

65Cenozoic

This long-bodied early whale still carried tiny external hind limbs.

74Recently extinct

The only seal endemic to the Caribbean rested and bred on warm sandy shores.

80Paleozoic

A slender body preserves repeated muscle blocks and internal traces important for interpreting early chordates.

81Paleozoic

Rows of scales and long spines armored this small seafloor grazer.

89Mesozoic

A long-necked coastal reptile paddled through shallow Triassic seas.

90Mesozoic

A massive pliosaur skull powered attacks on large marine prey.

98Recently extinct

One of the world’s largest freshwater fish migrated the length of the Yangtze.

99Recently extinct

This small sea duck had a specialized bill for feeding in shallow coastal water.

100Recently extinct

This large coastal sea lion bred on rocky islands across the Sea of Japan.

101Paleozoic

Paddle-shaped hind limbs carried this sea scorpion through shallow coastal water.

120Recently extinct

This palm-sized insect bat fell from island-wide abundance to a final acoustic signal in 2009.

137Paleozoic

Eyes sat at the ends of a crossbar and a long proboscis ended in a toothed grasping organ.

144Paleozoic

Branches more than a meter long carried dense narrow microphylls, far more elaborate than most naked-stemmed plants of its age.

160Recently extinct

Red-striped yellow-green tubular flowers opened among fleshy paired leaves; the last reliable sighting was in 1954.

161Precambrian

Its flat oval body moved across microbial mats like a rhythmically quilted cushion, leaving feeding traces behind.

162Precambrian

A horseshoe-shaped front led a body of offset leaflike units, giving it the appearance of a flattened soft worm.

163Precambrian

A featherlike body of repeating branches was anchored by a disc in deep water, yet it had neither chlorophyll nor a mouth.

164Precambrian

Its low oval body crawled across microbial mats while a front feeding structure left fan-shaped sets of scratches.

166Paleozoic

Its stout body hid in a U-shaped burrow while a spiny, hook-studded throat could turn inside out to seize food.

167Paleozoic

A broad head shield enclosed its front half, with forward-set eyes and a flexible tail behind the armored box.

170Mesozoic

Thirteen extremely elongated vertebrae formed a neck as long as half the body, while the skull snapped at fish and cephalopods.

173Mesozoic

Needle teeth lined long jaws while a diamond-shaped membrane at the stiff tail tip helped control flight above island seas.

174Mesozoic

This giant bony fish opened a broad mouth and strained plankton through dense gill rakers, much like a whale shark.

175Mesozoic

A short deep skull carried serrated blades, while this marine crocodile's body had transformed into four flippers and a fishlike tail.

176Cenozoic

Strong limbs could still bear weight, yet long feet paddled through water and the ear region was adapting to underwater sound.

177Cenozoic

Bundles of enamel-wrapped tooth columns and broad limbs helped it crop aquatic plants in tidal flats and shallow water.

189Mesozoic

Huge eyespots, broad wings and an elongate mouthpart created a butterfly-like insect before butterflies flourished.

190Mesozoic

Scaling from the surviving wing fragment suggests a wing as long as 16 centimeters, among the largest lacewings known.

194Mesozoic

Only about a centimeter long, it already folded spine-lined grasping forelegs beneath its chest.

201Precambrian

Rows of quilted sacks lived half-buried in sand, forming one of the Ediacaran seafloor's strangest communities.

202Precambrian

Six branching vanes surrounded a central axis, making the organism resemble a soft pine cone standing on the seabed.

203Precambrian

Three curving spiral arms created a body symmetry almost absent among living animals.

204Paleozoic

Ten pairs of stubby legs beneath a soft body place it near the early history of velvet worms and arthropods.

205Paleozoic

A pair of great appendages ended in three long whips that could sense, seize and move food.

206Paleozoic

A huge domed carapace covered its head, giving this radiodont the outline of a tiny finned submarine.

207Paleozoic

A straight conical shell several meters long made it one of the most conspicuous large cephalopods of Ordovician seas.

208Paleozoic

It lacked jaws and paired fins, but its head and gill region were enclosed within strong armor.

210Paleozoic

Flattened swimming paddles and great toothed claws made it a formidable hunter in Silurian water.

217Paleozoic

A long, tooth-filled snout gave this giant amphibian a gharial-like aquatic profile.

234Mesozoic

Its wings shrank to small bones while rear-set legs turned it into a superb Mesozoic pursuit diver.

235Mesozoic

Its body and flight resembled a tern, but a row of true teeth remained inside the long jaws.

236Mesozoic

An enormous crest rose above a short toothless beak, with soft tissue extending the bony sail still farther.

237Mesozoic

Four long flippers flew through water while a long flexible neck carried the small head toward prey.

238Mesozoic

A solid snout projected beyond the teeth as this giant mosasaur hunted fish, turtles and other reptiles.

239Mesozoic

Front flippers spanned several meters, and a leathery covering stretched over a reduced bony shell.

240Mesozoic

Huge bony eye rings supported vision under pressure and may have helped track soft prey in dim water.

250Cenozoic

Its estimated wingspan exceeded six meters, while bony pseudoteeth lined a beak adapted to slippery marine prey.

251Paleozoic

Its antennae, gills and clawed legs reveal far more than a mineralized trilobite shell.

252Paleozoic

Robust leg bases formed crushing jaws for small trilobites and other shelled prey.

253Paleozoic

Two large shields covered a soft body equipped with fully segmented trilobite-like limbs.

254Paleozoic

A bivalved carapace, paddle-like tail and brooded eggs reveal an early crustacean relative in detail.

255Paleozoic

At nearly seventy centimeters, it is among the largest complete trilobites ever found.

256Paleozoic

Its long pincers carried slanting blades suited to holding or slicing soft prey.

281Mesozoic

Two distinct tooth shapes gave this early pterosaur its name.

282Mesozoic

A toothed beak with matching crests helped seize slippery fish near the water surface.

283Mesozoic

An enormous branching crest crowned some adults, but there is no fossil evidence for a sail between its prongs.

284Mesozoic

A vast sail-like skull crest dominated the profile of this large toothless pterosaur.

285Mesozoic

More than a thousand bristle-like lower teeth formed a filter basket.

286Mesozoic

Flippers, a downturned tail fin and reduced armor transformed a crocodile relative into a pelagic swimmer.

287Mesozoic

A skull nearly two meters long and huge teeth formed an apex-predator bite apparatus.

288Mesozoic

More than sixty neck vertebrae formed an exceptionally long neck, while gastroliths filled the abdomen.

290Mesozoic

A reduced shell and giant front flippers made it one of the largest Cretaceous sea turtles.

295Cenozoic

A streamlined whale body still carried tiny external hind limbs with no walking function.

301Precambrian

Its quilted branches lay flat rather than rising from a stem.

302Precambrian

Dense stands of narrow tubes formed one of the earliest large colonial scenes.

303Precambrian

Bead-like discs arranged in strings may record an early macroscopic colony.

304Precambrian

Centimeter-wide ribbons curled into regular spirals among the earliest macroscopic fossils.

308Paleozoic

A flower-bud body carried five feeding and respiratory grooves.

309Paleozoic

Radiating septa inside a horn-shaped skeleton resemble a stone sun.

310Paleozoic

Linked tubes formed honeycomb chains across Paleozoic reefs.

311Paleozoic

Fine radial ribs covered rounded shells that once crowded ancient seabeds.

312Paleozoic

A broad hinge line formed stone wings that stabilized the shell on soft mud.

313Mesozoic

Its adult shell stretched into a near-straight rod while retaining ammonite sutures.

314Mesozoic

A huge internal shell identifies a large coleoidean, though total length remains uncertain.

315Mesozoic

The juvenile shell coiled tightly before the adult chamber uncoiled and hooked back.

317Mesozoic

Its huge upturned mouth could swallow fish nearly half its own length.

318Mesozoic

Oversized palatine fangs made a modest fish into a formidable midwater hunter.

320Paleozoic

An embryo with an umbilical connection records some of the earliest live birth.

321Paleozoic

This giant placoderm lacked sharp jaw blades and may have filtered plankton.

322Mesozoic

Broad crushing teeth paved its mouth for ammonites and shellfish.

326Mesozoic

A turtle-like shell protected a placodont with a broad filtering or scraping mouth.

328Mesozoic

A hammer-shaped snout scraped algae before needle teeth filtered the fragments.

334Mesozoic

Most of its enormous head crest was soft tissue used as a visual signal.

336Mesozoic

A waterbird close to ducks lived before the non-avian dinosaurs vanished.

339Recently extinct

Powerful legs and a heavy bill belonged to a flightless ground forager.

342Cenozoic

A bear-like carnivore used powerful jaws to pry and crush shellfish.

346Recently extinct

It was hunted out for fur before scientists could describe a living animal.

396Mesozoic

Raptorial forelegs and three tail filaments formed a lost mayfly body plan.

409Precambrian

Repeatedly branching cell filaments push green-plant history toward one billion years.

410Precambrian

Cell partitions and internal platelets were interpreted as very ancient red-algal evidence.

411Precambrian

A lobed multicellular thallus was proposed as an early red-algal body.

412Precambrian

Long carbonaceous ribbons resemble soft algae but lack diagnostic organs.

413Paleozoic

A perforated tube once treated as an animal is now linked to a branching alga.

414Paleozoic

Simple narrow blades radiated from a common attachment.

415Paleozoic

Spiraled diamond plates formed a calcified pinecone-like body.

416Paleozoic

Whorled calcified branches surrounded a central axis like an underwater bottlebrush.

417Mesozoic

Pink calcified masses were long assigned to red algae, but their identity is being reassessed.

418Precambrian

Branching cellular filaments show complex photosynthetic life before abundant animals.

429Paleozoic

A two-meter filter-feeding radiodont was an early analogue of giant plankton feeders.

430Paleozoic

A horseshoe-shaped carapace and rake-like appendages made a mobile sediment sifter.

431Paleozoic

An enormous head shield covered most of this bottom-feeding radiodont.

432Paleozoic

A spined bivalved shell enclosed a large-eyed swimming predator.

433Paleozoic

A broad head, long genal spines and many trunk segments marked an early trilobite radiation.

434Mesozoic

A coiled shell nearly two meters wide belonged to the largest known ammonite.

435Mesozoic

Rare soft tissues restore the ink sac, fins and ten hooked arms around an internal shell.

436Paleozoic

A two-meter eurypterid swept the bottom rather than sprinting after prey.

437Paleozoic

Placoderm armor enclosed jaw-margin bones resembling those of later bony fish.

439Mesozoic

A needle-like snout and slender body converged on modern barracudas.

440Mesozoic

Dorsal fin spines and two tooth shapes handled fish and hard-shelled prey.

441Paleozoic

Males carried a denticle-covered anvil-shaped structure on the back.

442Mesozoic

A giant bony fish filtered plankton near the ocean surface.

461Cenozoic

A one-and-a-half-meter penguin lived near the equator with a spear-like beak.

462Cenozoic

At almost 1.8 meters, it was a giant diver on a warmer Antarctic coast.

473Precambrian

Complex branching and septa make it a candidate early eukaryote or fungus.

477Precambrian

Circular carbon films may represent a giant single-celled eukaryote traditionally called an alga.

478Precambrian

Sausage-shaped carbon films may be macroalgae or another early eukaryote.

484Paleozoic

Two broad valves enclosed a segmented body while antennae, limbs and a tail fan projected outside.

485Paleozoic

Its nervous, circulatory and limb anatomy makes it central to studies of early arthropod organization.

486Paleozoic

Paired fins, a funnel and tentacle-like appendages form one of the Cambrian's most puzzling swimmers.

487Paleozoic

A coiled gut lay inside a soft circular disc that may have drifted or lived near the bottom.

488Paleozoic

A broad flat placoderm independently converged on the body shape of a ray.

489Paleozoic

Crescent-shaped lateral horns widened the head armor of a small bottom-dwelling placoderm.

495Mesozoic

A long snout, conical teeth and low crest belonged to a spinosaurid that frequently ate fish.

497Cenozoic

A near-six-meter wingspan and bony pseudoteeth armed a giant seabird.

511Paleozoic

Scales, long spines and a small front shell combined several Cambrian body plans.

512Paleozoic

A cup-shaped body attached by a long stalk and opened through a petal-ringed top.

513Paleozoic

A spiny head shield and specialized appendages belonged near the chelicerate stem.

514Paleozoic

Large pincer-like mandibles projected beneath a bivalved shell on an early mandibulate.

515Paleozoic

A broad bivalved shell enclosed most of the body and a three-pronged tail steered it.

516Paleozoic

A tiny armored body and pincer-like front appendages suggest an early chelicerate relative.

517Paleozoic

A broad flat shield with marginal spines and a leaf-like tail formed an unusual outline.

518Paleozoic

Long frontal appendages, side flaps and tail spines record a stem-panarthropod body.

519Paleozoic

Males carried a striking anvil-shaped brush-and-spine complex on the back.

520Paleozoic

A short snout, large eyes and pectoral structures belonged to an early chimaera relative.

521Paleozoic

High-set broad pectoral fins made this miniature holocephalan look winged underwater.

522Paleozoic

A spear-like rostrum and lateral horns projected from this jawless armored fish.

525Mesozoic

An extremely narrow snout gave this temnospondyl a gharial-like profile on an amphibian skeleton.

528Mesozoic

A narrow sensory-grooved snout suited an open-water temnospondyl.

531Mesozoic

A broad shell, toothless beak and crushing plates converged strongly on turtles.

534Mesozoic

A long tail, paddle-like limbs and downturned snout marked a vanished marine-reptile branch.

556Paleozoic

Large frontal appendages, rows of swimming flaps and an annulated soft body link lobopodians with true arthropods.

557Paleozoic

A pair of curved lower-jaw tusks and a kinetic skull helped this lobe-finned fish restrain prey.

558Paleozoic

A streamlined head shield extended into a rostrum, while a dorsal spine and lateral horns stabilized the jawless fish.

566Cenozoic

A near-human-height diving bird preserves feathers and melanosomes that opened direct study of ancient penguin color.

567Cenozoic

A slender trunk, long bill and large flippers produced a taller silhouette than modern penguins.