Sphenodiscus

SphenodiscusTemporal range: early Campanian-early Danian~83.5–64.5 Ma PreꞒ
Ꞓ
O
S
D
C
P
T
J
K
Pg
NframelessSphenodiscus lenticularisScientific classification link=Template:Taxonomy/Sphenodiscus|15x15px|Edit this classificationDomain:EukaryotaKingdom:AnimaliaPhylum:MolluscaClass:CephalopodaSubclass:†AmmonoideaOrder:†AmmonitidaFamily:†SphenodiscidaeGenus:†SphenodiscusMeek 1871Species S. lobatus (Tuomey, 1854 [originally Ammonites lobatus])
 S. lenticularis (Owen, 1852 [originally Ammonites lenticularis])
 S. pleurisepta (Conrad, 1857 [originally Ammonites pleurisepta])
 S. brasiliensis Maury, 1930
 S. binkhorsti Böhm, 1898
 S. intermedius Böse, 1927
 S. aberrans Böse, 1927
 S. parahybensis Maury, 1930
 S. prepleurisepta Böse, 1927
 S. ubaghsi de Groussouvre, 1894
 S. siva Kennedy & Henderson, 1992
Category:Articles with 'species' microformats

Sphenodiscus Wani barewa ne na acanthoceratacean ammonite. An samo nau'in jinsin daga nahiyoyi da yawa kuma ana tunanin ya sami babban rarraba a duniya a lokacin Maastrichtian mataki na Late Cretaceous.Ya kasance ɗaya daga cikin ammonoids na ƙarshe da suka samo asali kafin gabaɗayan rukunin su zama batattu a lokacin Paleocene, wanda ya kasance kai tsaye bayan taron bacewar Cretaceous–Paleogene.
An gano burbushin halittu a ko'ina cikin Arewacin Amirka daga yankuna a Kudancin Carolina, North Carolina, South Dakota, Maryland, New Jersey da Mexico. Har ila yau,akwai shaidar jinsin da ke kasancewa daga tsibirin Trinidad,ko da yake ba za a iya rarraba kayan da aka samo daga nan ba a matakin jinsin. Yawancin nau'ikan da ake samu a Arewacin Amurka sun haɗa da S.lobatus,S.lenticularis, da S.pleurisepta. An samo sabbin nau'ikan daga yankuna a wajen Arewacin Amurka kamar S.binkhorsti daga Tsarin Maastricht a cikin Netherlands,S.siva daga Tsarin Valudavur a Indiya da S.brasiliensis daga gadaje tare da bankunan Rio Gramame a Brazil.   An kuma sami samfurori da yawa na S.lobatus daga Nkporo Shale a Najeriya.

An daidaita harsashi na Sphenodiscus kuma daga baya an matse shi tare da magudanar ruwa da ƙaramar cibiya.Gefen huhu na harsashi yana mai da hankali sosai.Filayen waje gabaɗaya santsi ne a cikin samfuran burbushin halittu,kodayake wasu nau'ikan a matakai daban-daban na ci gaban ontogenic na iya mallakar ƙananan tubercles masu yawa tare da saman su. Sphenodiscus yana da tsari mai sarƙaƙƙiya mai sarƙaƙƙiya tare da ƙananan ƙananan lobes da sirdi masu yawa.

 Nassoshi