2003), disarticulated cephalaspids, placoderms and acanthodians, and both articulated and disarticulated eurypterids (Miller 2007a).
2003), suggesting that eurypterids, cephalaspids, chondrichthyans and acathodians may have migrated across paleoenvironments.
, large arthrodires and sarcopterygians, show that the lowermost part of the Razvedochnyj Fm is exposed.
For many years scientists have studied fossils of cephalaspids
, which had heads shaped like horseshoes, and puzzled over how the creatures might have propelled themselves.
These previously discovered eurypterids are from the western exposure of the Campbellton Formation and are believed to have inhabited a coastal deltaic setting, along with a rich vertebrate assemblage that included cephalaspids
, placoderms, acanthodians, and sharks.
However, a cephalic organ is present in some cephalaspids
(Schaeffer and Ruthensteiner, 2001) and nudibranchs (Chia and Koss, 1984).