Tetragonites superstes Hoepen 1921 from: Ifrim, C..Stinnesbeck, W..López-Oliva, J.G.. (2004): Maastrichtian cephalopods from Cerralvo, north-eastern Mexico . Palaeontology Vol. 47(6) p. 1575–1627 . |
Notice: This catalogue page may contain unedited data.
|
Species Tetragonites superstes Hoepen 1921 |
|
[1] Text-fig. 3E-G Ifrim et al. (2004) [2] pl. 1, figs. 5-8 Ifrim et al. (2004)
|
Diagnosis / Definition: |
Ifrim et al. (2004):
Description: Small and involute speeies with a moderate expansion rate. The whorl seetion is subreetangular to
subelliptieal with maximum whorl breadth below midflank. The umbilieus is 0·24-0·31 of the shell diameter, rather
deep, with a subvertieal wall and previous whorls visible. The umbilieal shoulder is abruptly rounded. The flanks are
gently rounded to parallel and grade into broadly rounded eonvergent ventrolateral shoulders. Venter flattened. From a
diameter of c. 15mm on some speeimens show faint grooves on the ventral margins that parallel a faint ridge on eaeh
umbilieal shoulder. Internal moulds are smooth, but faint prorsiradiate growth striae are visible on internal whorls. The suture line has a large asymmetrie trifid first lateral saddle (EIL), a smaller trifid seeond lateral saddle (LlU2), and a suspensive lobe with a large trifid first auxiliary saddle. The first lateral lobe (L) is large and irregularly subdivided. The first of the four auxiliary lobes is trifid. These features are displayed through all growth stages documented here, but their dimensions and grades of ineision inerease eonsiderably. |
Discussion / Comments: |
Ifrim et al. (2004):
Remarks: Tetragonites superstes resembles T. epigonus (Kossmat, 1895), but is less involute and less
expanded during growth. According to Kennedy and Klinger (1977), T. popetensis (Yabe, 1903) is another
species with similar morphology. lt ranges from the Campanian to the Maastrichtian, and is known from
California and Japan. However, this species differs by the presence of constrictions that are marked clearly
on the shell. All other Tetragonites species are ornamented by distant ribs or constrictions.
Occurrence: Tetragonites superstes van Hoepen has only been described from the Upper Santonian or Lower
Campanian of South Africa (Kennedy and Klinger 1977) and Lower-Middle Campanian of Madagascar (Collignon
1956). |
Systematics: |
36 Ordo Ammonoidea
Subordo Lytoceratina
Superfamilia Tetragonitaceae
Familia Tetragonitidae
Subfamilia Tetragonitinae
Genus Tetragonites
Species Tetragonites superstes
|
Synonym list: |
Ifrim et al. (2004):
|
Stratigraphy - relative ages: |
middle Campanian - upper Santonian: Ifrim et al. (2004)
|
References: |
Spath,L.F.. (1921): On Upper Cretaceous Ammonoidea from Pondoland . Annals of the Durban Museum Vol. 3 p. 39-57
Hoepen,v.E.C.N.. (1921): Cretaceous Cephalopoda from Pondoland . Annals of the Transvaal Museum, 8, 1–48. Vol. 8 p. 1-48
Spath,L.F.. (1922): On the Senonian ammonite fauna of Pondoland . Transactions of the Royal Society of South Africa Vol. 10 p. 113–148
COLLIGNON,M.. (1956): Ammonites neocretacees du Menabe (Madagascar) IV. - Les Phylloceratides; V. - Les Gaudryceratides; VI. - Les Tetragonitidae. . Annales Geologiques du Service des Mines de Madagascar Vol. 23 p. 1-106
COLLIGNON,M.. (1969): Atlas des fossiles caracteristiques de Madagascar (Ammonites). (Campanien inferieur). Vol. 15 p. 216 pp
Kennedy,W.J.. and KLINGER,H.C.. (1977): Cretaceous faunas from Zululand and Natal, South Africa. The ammonite family Tetragonitidae Hyatt, 1900 . Annals of the South African Museum Vol. 73 p. 149-197
Ifrim,C..; Stinnesbeck,W.. and López-Oliva,J.G.. (2004): Maastrichtian cephalopods from Cerralvo, north-eastern Mexico . Palaeontology Vol. 47(6) p. 1575–1627
|
This work is licensed under a Creative Commons Attribution 2.5 License.
|
|