Coeloptychium

Coeloptychium is an extinct genus of lychniscosidan hexasterophoran sea sponge which has often been used as an index fossil.^[1] Its remains have been found in Cretaceous sediments in Germany, Belgium, France and the UK.^[2] Coeloptyhcium is best preserved in Campanian sediments in Germany. The type species, C. agaricoides, was named in 1826.

Coeloptychium Temporal range: Cretaceous, 112–66 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Fossil of Coeloptychium agaricoides from the Campanian of Misburg, Lower Saxony
Scientific classification
Kingdom:	Animalia
Phylum:	Porifera
Class:	Hexactinellida
Subclass:	Hexasterophora
Order:	Lychniscosida
Family:	†Coeloptychidae Roemer, 1864
Genus:	†Coeloptychium Goldfuss, 1826
Subgenera
Lophoptychium Pomel, 1872 Myrmecioptychium Scrammer, 1912

Species

• Coeloptychium agaricoides Goldfuss, 1826
• Coeloptychium deciminum Roemer, 1841
• Coeloptychium incisum Roemer, 1841
• Coeloptychium princeps Roemer, 1861
• Coeloptychium rude Zittel, 1876
• Coeloptychium seebachi Zittel, 1876
• Coeloptychium subagaricoides Sinov, 1871
• Coeloptychium sulciferum Roemer, 1841