Phymosomatoida
Encyclopedia
The Phymosomatoida are an order
of sea urchin
s, found in Europe, Nort America, North Africa and the Middle East.
They are distinguished from other sea urchins by the presence of large fused plates on top of the feeding lantern. The test is usually sculpted to some degree, but, unlike their close relatives the Temnopleuroida
, the tubercles are never perforated. The opening in the test through which the anus passes, known as the periproct, is unusually large in sea urchins from this group. The apical disc, around the mouth, is only loosely attached to the rest of the test and is often missing in fossil species, giving the false impression that they also have a large oral opening.
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
of sea urchin
Sea urchin
Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...
s, found in Europe, Nort America, North Africa and the Middle East.
They are distinguished from other sea urchins by the presence of large fused plates on top of the feeding lantern. The test is usually sculpted to some degree, but, unlike their close relatives the Temnopleuroida
Temnopleuroida
The Temnopleuroida are an infraorder of sea urchins in the order Camaradonta. They are distinguished from other sea urchins by the presence of large fused plates on top of the feeding lantern. The test is usually sculpted to some degree, and has perforated tubercles.Temnopleuridea is now the...
, the tubercles are never perforated. The opening in the test through which the anus passes, known as the periproct, is unusually large in sea urchins from this group. The apical disc, around the mouth, is only loosely attached to the rest of the test and is often missing in fossil species, giving the false impression that they also have a large oral opening.