Lytocrioceras Explained

Lytocrioceras is a genus of ancyloceratine ammonites from the Lower Cretaceous with a shell that resembles a safety pin. The shell begins as a loosely wound spiral, followed by a straight shaft which makes a U-turn to go back is somewhat the opposite direction, ending in a jog, offset from the original coil.

Lytocrioceras was originally included in the Ancyloceratidae (Lytoceratina),^[1] united with other similar forms but has since been reassigned to the Macroscaphitidae.^[2]

Notes and References

1. Book: W.J. . Arkell . B. . Kummel . C.W. . Wright . Treatise on Invertebrate Paleontology, Part L, Mollusca 4. Mesozoic Ammonoidea . Geological Society of America and University of Kansas Press . Lawrence, Kansas. 1957.
2. Vermeulen . J. . 1999 . New data on the stratigraphical ranges, the evolutions and the classifications of three lower Cretaceous ammonites families . Géologie Alpine . 75 . 123–132 .