Post by tqb on Jan 10, 2015 15:42:46 GMT -5
It's not Palaeozoic but is quite exotic and extremely rare (in articulated versions anyway).
Plumaster sp., probably P. ophiuroides Wright, 1863 but the holotype of that species, which is the only described specimen, is the other way up. Pliensbachian, probably Davoei Zone (top of the Lower Lias)
I found it about 3 years ago on the Yorkshire coast, and prepped grain by grain under a microscope (air abrader was too risky). I guess it took about 150 hours but I think it was worth it.
The mono-generic family Plumasteridae was erected recently (by Gale, 2011) with the most obvious diagnostic feature being the ossicles with bosses for spine articulation, similar to echinoids. True sunstars (solasteridae) don't have them.
The specimen is about 8cm across, estimated whole diameter of about 10 - 11cm.
Plumaster sp., probably P. ophiuroides Wright, 1863 but the holotype of that species, which is the only described specimen, is the other way up. Pliensbachian, probably Davoei Zone (top of the Lower Lias)
I found it about 3 years ago on the Yorkshire coast, and prepped grain by grain under a microscope (air abrader was too risky). I guess it took about 150 hours but I think it was worth it.
The mono-generic family Plumasteridae was erected recently (by Gale, 2011) with the most obvious diagnostic feature being the ossicles with bosses for spine articulation, similar to echinoids. True sunstars (solasteridae) don't have them.
The specimen is about 8cm across, estimated whole diameter of about 10 - 11cm.
