Archaeocidaris nearly complete "Aristotle's Lantern" mouth structures and associated plates and spines!

[Tom Olson]

An update on Oral Plates of Archaeocidaris of the Pennsylvanian Naco Formation, Central Arizona. Below shows about three to four collapsed urchins with their associated plates and spines and occasional oral plates articulated. c.2022 T.J. Olson. Urchin3 has "complete Aristotle's Lantern " with about three teeth on the surface and associated Hemi-pyramids and Rotulas ( Circled). Urchin 5 is a close up of the Lantern or Urchin3. Urchin 4 is a close up of spines with barbs oriented in same direction away from the broken lantern to the left of the spines. Very rare in the Paleozoic.

 

 

 

 

 

[erose]

Nice! could be worth a better prep with an air abrasive tool.