Paleozoic

04Paleozoic

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

15Paleozoic

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

17Paleozoic

This many-segmented arthropod grew longer than a person in coal-swamp forests.

18Paleozoic

This sail-backed predator was closer to mammals than to dinosaurs.

19Paleozoic

A beaked, tusked survivor became extraordinarily common after Earth’s greatest mass extinction.

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.

33Paleozoic

This giant sea scorpion may have exceeded two meters in length.

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.

37Paleozoic

Bones inside its fleshy fins foreshadowed the limb pattern of land vertebrates.

38Paleozoic

Long saber canines armed one of the largest predators of the latest Permian.

39Paleozoic

A barrel-bodied herbivore carried bony armor beneath its skin.

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.

82Paleozoic

A flat-headed fish with a mobile neck and wrist-like fin bones approached the anatomy of early tetrapods.

83Paleozoic

This griffinfly’s wings spanned roughly seventy centimeters above Carboniferous forests.

84Paleozoic

A thick skull roof capped this heavy plant-eating mammal relative.

101Paleozoic

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

102Paleozoic

Bony armor enclosed its head and chest while jointed pectoral appendages steadied it on the bottom.

103Paleozoic

Weight-bearing limbs accompanied a fish-like tail in an animal still deeply tied to water.

104Paleozoic

This tiny insect hunter belonged to an early generation of vertebrates freed from laying eggs in water.

105Paleozoic

Crossbars projected from the spines of its tall sail above a broad plant-processing body.

121Paleozoic

Leafless stems only centimeters tall held spore capsules at their tips, marking an early step inland.

122Paleozoic

Naked upright axes rose from creeping rhizomes, preserved cell by cell by silica-rich hot springs.

123Paleozoic

It grew true wood and a tree crown but still reproduced by spores, helping create Earth's first broad forests.

124Paleozoic

A straight trunk patterned with diamond leaf scars forked only high above the Carboniferous mire.

125Paleozoic

Casts of jointed stems record large horsetail relatives; Calamites suckowii does not automatically name a plant with all organs known.

126Paleozoic

Woody stems carried immense fernlike fronds, yet seeds grew among the foliage of this vanished seed fern.

127Paleozoic

Tongue-shaped leaves across the southern continents became important evidence that Gondwana was once united.

137Paleozoic

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

138Paleozoic

Paired bony bosses formed a rough crown on the skull of this large, probably plant-eating therapsid.

141Paleozoic

Leafless axes rose in stands from creeping stems; conducting cells were present, but true vascular tissue was not.

142Paleozoic

Short axes carried forked sporangia above corm-like bases that could resprout on a repeatedly flooded hot-spring surface.

143Paleozoic

Veinless leaf-like flaps covered its axes, while star-shaped xylem supplied shoots that rose nearly half a meter.

144Paleozoic

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

145Paleozoic

Naked axes forked repeatedly, their fertile tips curling inward and carrying paired elongated sporangia.

146Paleozoic

Two rows of kidney-shaped sporangia lined curved branch tips like the teeth of an unfinished botanical zipper.

147Paleozoic

Vertical rows of leaf scars stamped the tall trunk, beneath a crown of sparse branches and grasslike microphylls.

148Paleozoic

Rounded pinnules carried fanlike veins and looked fernlike, yet immense seeds grew among the fronds.

149Paleozoic

Clusters of long strap-shaped leaves crowned woody trees from an extinct gymnosperm lineage near early conifers.

150Paleozoic

Six wedge-shaped leaves encircled each node of a slender stem that trailed across the ground or climbed larger trees.

165Paleozoic

Two pairs of curved head spines, long antennae and dozens of fine legs made this two-centimeter arthropod exquisitely elaborate.

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.

168Paleozoic

This giant lobe-finned predator used fanglike teeth to ambush prey, while its fin skeleton followed a tetrapod-like pattern.

169Paleozoic

A tiny head joined a barrel-shaped giant body whose broad ribs enclosed a vast plant-fermenting digestive system.

181Paleozoic

A patterned wing only about two centimeters across pushes the secure record of insect flight into the Early Carboniferous.

182Paleozoic

Beyond four wings packed with netlike veins, the thorax carried a pair of small immobile winglets.

183Paleozoic

Scaling from the surviving giant wing suggests a four-winged span near half a meter, among the largest palaeodictyopterans known.

184Paleozoic

The largest estimates reach a 71-centimeter wingspan, placing it among the biggest flying insects in Earth history.

185Paleozoic

Banded dark patterns remain on its fossil wings, returning color pattern to a Permian insect rather than a blank outline.

186Paleozoic

A wing resembling that of a crane fly was once treated as an early dipteran clue, but its true affinity remains disputed.

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.

209Paleozoic

Sensory fields beneath a broad crescent-shaped head shield helped it search through turbid bottom water.

210Paleozoic

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

211Paleozoic

A flat head with upward-facing eyes and limb-like bones inside its fins brought it close to the earliest tetrapods.

212Paleozoic

Each forelimb carried eight digits, yet the animal was still mainly aquatic—digits evolved before true land walking.

213Paleozoic

Its skull spread sideways into a boomerang, perhaps producing lift in current or making it hard to swallow.

214Paleozoic

A broad, heavily sculpted skull and strong limbs carried its massive body through shallow water and onto banks.

215Paleozoic

Its adult skeleton looked reptile-like, yet it belonged just outside the fully land-breeding amniotes.

216Paleozoic

A high bony sail towered above the squat body and may have served display, recognition or heat exchange.

217Paleozoic

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

218Paleozoic

A beak, short tusks and powerful forelimbs made this one of the most common burrowing herbivores of the Late Permian.

219Paleozoic

Long upper canines and a wide gape made it an early experiment in saber-toothed predation.

220Paleozoic

Nine pairs of broad, flattened ribs record an early stage in the evolution of the turtle shell.

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.

257Paleozoic

Rows of paired ventral spines formed a defensive fence beneath this small early jawed fish.

258Paleozoic

Its body was a flattened shield with upward-facing eyes and a mouth beneath the front edge.

259Paleozoic

An eel-like body, continuous fin and spine behind the head made it unlike any modern shark.

260Paleozoic

A single head spine, forked teeth and continuous dorsal fin defined this freshwater shark.

261Paleozoic

Its long skull and deep tail suggest a waterside animal that was still a capable walker.

262Paleozoic

Low vertebral ridges accompanied a deep skull and strongly differentiated teeth.

263Paleozoic

A light build, long limbs and small skull bosses combine primitive and therapsid features.

264Paleozoic

A huge skull combined thickened impact surfaces with long canines in a formidable predator.

265Paleozoic

A domed, massively thick skull crowned the barrel body of this giant herbivore.

306Paleozoic

Branching microscopic hyphae show fungi helping to build the earliest soils.

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.

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.

325Paleozoic

Tiny limbs and strong jaws show an early tetrapod returning almost completely to water.

355Paleozoic

A frog-like head and salamander-like tail combine traits near the origin of living amphibians.

359Paleozoic

An elongated nostril region may reflect life in drier upland settings.

360Paleozoic

More than forty trunk vertebrae formed a long body with extremely small limbs.

361Paleozoic

Adults retained external gills, extending a juvenile condition through life.

362Paleozoic

Forward-facing toes show an early tetrapod using a more effective terrestrial gait.

363Paleozoic

A reinforced skull and fang-like teeth belonged to a powerful river predator.

364Paleozoic

A long trunk and deep tail propelled it through murky water.

365Paleozoic

The ear region and sturdy limbs suggest more terrestrial activity than in many contemporaries.

366Paleozoic

Many individuals were entombed inside hollow tree stumps.

367Paleozoic

A row of bony back plates reinforced this stocky terrestrial amphibian.

368Paleozoic

A serrated rear skull margin may have protected the neck or supported soft tissue.

371Paleozoic

This broad-headed aquatic predator was common in southern Late Permian waters.

373Paleozoic

The limbs vanished entirely while the skull and spine retained tetrapod construction.

376Paleozoic

A long snout, lateral-line grooves and weak limbs show permanent aquatic dependence.

390Paleozoic

Broad net-veined wings carried an early aerial predator through oxygen-rich forests.

391Paleozoic

Huge triangular wings and long tail filaments belonged to a giant mayfly relative.

392Paleozoic

Thoracic winglets accompanied four large wings in an extinct flight architecture.

393Paleozoic

A shield-like pronotum and flat wings mark an early cockroach-mantis relative.

394Paleozoic

An enlarged prothorax carried a row of prominent spines.

395Paleozoic

Its wing venation pushes the cockroach-like pattern deep into the Carboniferous.

399Paleozoic

Meter-high columns towered over landscapes of otherwise low vegetation.

400Paleozoic

Tiny flask-shaped fruiting bodies inside plant tissue are among the oldest ascomycete evidence.

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.

419Paleozoic

Eight-meter leafless crowns formed one of the earliest known forests.

422Paleozoic

Broad tongue-shaped leaves lacked the strong midrib of later glossopterids.

423Paleozoic

Firm fern-like pinnules belonged to a seed plant rather than a true fern.

425Paleozoic

A wingspan near half a meter made it a major aerial predator.

426Paleozoic

Leaf-like thoracic lobes accompanied four functional wings.

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.

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.

438Paleozoic

Huge conical teeth armed a multi-meter freshwater lobe-finned predator.

441Paleozoic

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

443Paleozoic

Paired backward horns widened the skull of this small diplocaulid.

446Paleozoic

A small light body combined traits near the ancestry of modern amphibians.

475Paleozoic

Tiny sac-like structures in coal balls resemble an early ascomycete.

476Paleozoic

Fungal filaments surrounded cyanobacterium-like cells in an early lichen-style partnership.

479Paleozoic

A palm-like crown belonged not to a fern but to an extinct heterosporous seed-plant relative.

480Paleozoic

Hollow jointed stems let an early horsetail relative grow as a tall shrub or small tree.

481Paleozoic

Shield-shaped reproductive discs record an innovation among drought-tolerant seed ferns.

482Paleozoic

Smaller than Meganeura but still broad-winged, this griffinfly hunted above coal forests.

483Paleozoic

A long piercing mouthpart and four patterned wings belonged to the vanished palaeodictyopterans.

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.

490Paleozoic

External gills and a long body show a temnospondyl that remained aquatic throughout life.

491Paleozoic

A broad head, strong trunk and compressed tail belonged to a large freshwater predator.

493Paleozoic

Needle teeth and a flattened tail mark one of the earliest amniotes to return to water.

501Paleozoic

Diamond leaf cushions and a repeatedly forked crown marked a tall tree-sized lycopsid.

502Paleozoic

Narrow leaves repeatedly forked at their tips on an extinct seed-plant relative.

503Paleozoic

Needle-like leaves crowded the shoots of an early conifer-like tree.

506Paleozoic

Four broad net-veined wings belonged to the completely vanished palaeodictyopterans.

507Paleozoic

A basal odonatopteran retained a more primitive wing base than modern dragonflies.

508Paleozoic

A wingless body ended in three tail filaments and combined traits of early silverfish-like insects.

509Paleozoic

Spotted wings and fine venation record Permian palaeodictyopteran diversity.

510Paleozoic

Long transparent net-veined wings record an early radiation of large flying insects.

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.

523Paleozoic

A streamlined shield extended into a pointed snout and carried a stabilizing dorsal rise.

524Paleozoic

A long rostrum, side horns and paired openings belonged to an endemic jawless armored lineage.

526Paleozoic

A tiny body and retained gill structures marked a branchiosaurid amphibian.

527Paleozoic

A short trunk, mobile neck and ear region approach the body plan of modern amphibian ancestors.

529Paleozoic

A broad flat head, strong trunk and compressed tail belonged to a large aquatic predator.

530Paleozoic

A long neck, tail and webbed feet show an early diapsid frequently entering water.

532Paleozoic

Long independent bony rods supported one of the earliest vertebrate gliding membranes.

554Paleozoic

Carbonized cell sheets and tangled tubes came from an enigmatic early terrestrial organism.

555Paleozoic

Two pairs of net-veined wings could not fold, and some species carried thoracic winglets and piercing mouthparts.

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.

559Paleozoic

Tiny rhomboid scales, a deeply forked tail and broad gape marked an early ray-finned fish radiation.

560Paleozoic

A broad flat skull and dense pointed teeth belonged to a large aquatic temnospondyl.