Hypophylloceras

Hypophylloceras Temporal range: Valanginian–Maastrichtian [1] PreꞒ Ꞓ O S D C P T J K Pg N
A fossil of Hypophylloceras subramosum in Toyohashi Museum of Natural History
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	† Ammonoidea
Order:	† Ammonitida
Family:	† Phylloceratidae
Subfamily:	† Phylloceratinae
Genus:	† Hypophylloceras Salfeld, 1924

Hypophylloceras is a Cretaceous ammonite with a finely ribbed, compressed, involute shell; some having periodic stronger ribs or folds. The suture is complex, with large, asymmetric and finely divided lobes; the 1st lateral being much larger than the external (=ventral) and 2nd lateral lobes. Saddle endings commonly not phylloid. ^[2]

Hypophylloceras includes Neophylloceras Shimizu 1934 (=Paraphylloceras Chimisu 1935 ), Hyporbulites Brestroffer 1947, Goretophylloceras Collingnon 1949 and Aphrotiticeras Mahmoud in Breister, 1952. ^[2]

The type species Hypophylloceras ononense, named by Salfeld in 1924 and based on Phylloceras ononense Santon 1895, comes from the Aptian of California.

References

1. Sepkoski, Jack (2002). "Sepkoski's Online Genus Database" . Retrieved 2014-05-28.
2. Arkell, W.J.; Kummel, B.; Wright, C.W. (1957). Mesozoic Ammonoidea. Treatise on Invertebrate Paleontology, Part L, Mollusca 4. Lawrence, Kansas: Geological Society of America and University of Kansas Press.

• Imlay 1960. Early Cretaceous (albian) Ammonites from the Chitina Valley and Talkeetna Mountains, Alaska. US Geological Survey PP 354-D
• Hypophylloceras entry in the Paleobiology Database 5/02/12