Spyroceratidae
| Spyroceratidae | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Cephalopoda |
| Order: | †Pseudorthocerida |
| Family: | †Spyroceratidae Shimazu & Obata 1935 |
Spyroceratidae are defined[1] as Pseudorthocerida with uniformly slender siphuncle segments, longer than wide, that contract sharply near either end, in which endosiphuncular deposits first form a compete annulus before fusing ventrally.
References
[edit]- ^ Sweet, Walter C. 1964. Nautiloidea -Orthocerida. Treatise on Invertebrate Paleontology, Part K. Geological Soc. of America and Univ of Kansas press
Notable fossil cephalopods (listed by first occurrence) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Cenozoic |
| ||||||||
| Mesozoic |
| ||||||||
| Palaeozoic |
| ||||||||
| Misidentified |
| ||||||||
