Chelicerata

Question 1

Chelicerata General Info

Answer 1

Cambrian to recent
Chelicerae: first pair of appendages on third segments
No antennae or mandibles
Living examples - horseshoe crabs, scorpions, sea spiders

Question 2

Xiphosura / Horseshoe Crabs

Answer 2

Silurian to recent
Family limulidae
Very durable, but only 4 modern species
Live near the coast - not great swimmers
Blood is valuable in the medicinal field

Question 3

Eurypterida / “Sea Scorpions”

Answer 3

Ordovician to Permian
Prosoma, abdomen, telson
Free swimming + crawling - major ocean predators
Many lived in shallow waters - could have ventured on land to hunt

Question 4

Araneae

Answer 4

Pennsylvanian to recent
8 legs and (mostly) 8 eyes

Question 5

Scorpiones

Answer 5

Silurian to recent
8 legs
Highly modified telsons - can sting
Exoskeletons glow under UV light

Question 6

Acari / Ticks + Mites

Answer 6

Devonian to recent
Typically ectoparasites
Not great fossil record