Invertebrates

04Paleozoic

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

17Paleozoic

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

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.

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.

101Paleozoic

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

137Paleozoic

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

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.

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.

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.

210Paleozoic

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

221Mesozoic

This lightly built two-meter hunter represents an early branch from the first dinosaur diversification.

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.

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.

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.

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.

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.

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.

556Paleozoic

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