Archaeocidaris oral plates from the Pennsylvanian Naco Formation of Central Arizona!

[Tom Olson]

Below shows individual "oral plates" of Aristotle's Lantern of Archaeocidaris from the Naco Formation ( Middle Pennsylvanian), Central Arizona. A= Teeth, B=Hemi-pyramids, C=Rotula brace,

D=Pentameral plate, E=spine with barbs. All items were discovered in a thin horizon of shale and limestone with about 9 collapsed urchins. Slabs of limestone also contain nearly complete 
"Aristotle's Lantern" with plates and spines surrounding and attached together. Additional photo shows the sketches of oral plates and functions of each.

Ref: Oral Plates of Archaeocidaris from the Naco Formation ( Middle Pennsylvanian), Central Arizona., McCord, R.D, and Boaz, D., eds, Southwest Paleontological Society, Mesa Southwest Museum Bulletin No. 6, 1999, pp9-14.

[DPS Ammonite]

Welcome aboard Tom. I love the sponge that was named after you, Chaunactis olsoni. Did you know that one member found them in

New Mexico?

 

 

Met you at GSA in Phoenix with Spencer. 
 

Cool Tom. Never seen the mouth parts of a Naco urchin.

 

Have any even partially articulated urchins been found in the Naco?

 

John

 

Edited September 1, 2022 by DPS Ammonite

[Tidgy's Dad]

Very interesting finds. 

Thank you for sharing. 

[Tom Olson]

Hii now have some articulated Aristotle's lantern urchin mouths in situations! I just can't seem to upload photos yet! Found in the Naco fm!