perekond

Nereites (trace fossil) circinalis (Heer, 1877)

Taksoni kirjeldused

Wetzel & Uchman, 1997

Emended diagnosis: Nereites with segments of burrows arranged in one or two spiral whorls.

Description: Winding strips spirally coiled at one end, preserved in full-relief (strongly flattened) in epichnial position or compressed tubes adhering to the sole of bed. The strips are 4-6 mm wide, and the spirals display 1-2 whorls and are up to 15-45 mm in diameter (Figs. 4C-E). In a few cases, an indistinct lobate, reworked zone can be observed along the strips, but only in thin sections. Remarks: The indistinct lobate, reworked zone is the diagnostic feature of Nereites.