30352 - Rare 2.28 Inch Ectillaenus katzeri Ordovician Trilobite - Czech Republic Hatangia scita The cow sharks are considered

The cow sharks are considered the most primitive ones because they preserve a skeleton anatomy very similar to the ancient and first types of sharks

† Annularia sp

Dolichoagnostus

Geyer and E

Hypermecaspis

30352 - Rare 2.28 Inch Ectillaenus katzeri Ordovician Trilobite - Czech Republic Hatangia scita The cow sharks are consideredEctillaenus, Salter 1867 (trilobite) Trilobita Corynexochida Illaenidae PaleoDB taxon number: 19550 Parent taxon: Illaenidae according to P. A. Jell and J. M. Adrain 2002 See also Sepkoski 2002 Sister taxa: Bumastoides, Bumastus, Caudillaenus, Cryptonymus, Deucalion, Dysplanus, Eastonillaenus, Harpillaenus, Hyboaspis, Hydrolaenus, Illaeninae, Illaenus, Nanillaenus, Octillaenus, Panderinae, Parillaenus, Platillaenus, Ptilillaenus, Stenopareia,