Ecdysozoans

Agnostid

Cambrian

planktonic because geographically widespread and found in many species

in c to ordo were mostly in deep water and low oxygen facies

dont have eyeballs, same front and back, very few thoracic segments

Ptychopariids

Elrathia kingi

early-Middle Cambrian

outer shelf to slope env

Redlichiids - first trilobites

Olenellus

Low to mid Cambrian

outer shelf/offshore

Redlichiids

Paradoxies

Middle Cambrian

outer shelf/offshore

Trinucleids

Cryptolithus

Upper Ordovician

have long hair 

offshore below normal storm wave base but can be affected by hurricanes

Trinucleids

Trinucleus

Middle Ordovician

empanada wala 

offshore below normal storm wave base but can be affected by hurricanes

Phacopids

Phacops

Devonian

schizochroal eyes, has bumps on body

offshore

Phacopids

Flexicalymene

Ordovician

can roll, can see indents in globula

offshore

Rusophycus

Cruziana

Chelicerates

Eurypterus ramipes

Silurian

mouth parts are chelicerae or claw like/pincers

Chelicerates

Horseshoe crabs

Early Ordovicianto to recent

living fossil, chelicerae

nearshow, shallow subtidal

Mortichnia- crab and trace together

atlantic horseshow crab - limulus polyphemus

Barnacles

Ordovician to recent

marine intertidal to subtidal, high energy settings

Hermit crab

Jurassic to recent

intertidal to offshore

Ghost Shrimp

Callianassa

everywhere, nearshore, lower foreshore env

jurassic onwards

Ophiomorpha - callianassa trace fossil

lagoon/beach/foreshore

jurassic onwards

Thalassinoides- callianassa burrows

ghost crab

psilonichus is the y-shaped burrow they make.

subtropical, tropical shorelines

fiddler crabs

world wide distribution

psilonichus is the j-shaped burrow they make.

one big arm

leperdita - ostracod

ordovician

freshwater to marine all depths- paleoclimate and salinity indicators