Stenaster salteri
Phylum Echinodermata, Order Ophiuroidea, Family Stenasteridae
Geological Time: Middle Ordovician (~ 461-449 million years ago)
Size): Fossil is 30 mm and 28 mm across on a 112 mm by 80 mm matrix
Fossil Site: Bobcaygeon Formation, Ontario, Canada
Code: AW112
Price: Sold
 Description:
This is a most unusual brittlestar in that it  is
most starfish-like in its exterior morphology. While it has a “typical”
starfish shape with short, wide arms, it lacks the madreporite and
ambulacral grooves of a true starfish. Stenaster is interpreted as
an ophiuroid which has secondarily adopted a deposit-feeding mode
of life, analogous to that of some extant asteroids, making it convergent
on the true starfish (asteroids). This one is seen with some other
associated material, including arms of a second example. |
