Libycoceras acutodorsatus Noetling 1897 (TaxonConcept

Taxon Concept provided by
Home \| Search

Back to Search

Anonymous: Unedited TaxonConcept data

Notice: This catalogue page may contain unedited data.

Species Libycoceras acutodorsatus Noetling 1897

Diagnosis / Definition:

FATMI & Kennedy (1999):
Description.-GSP 1054: internal mold of adult with phragmocone 74.6 mm diameter, plus 45 degree sector of body chamber with maximum preserved diameter 82.5 mm. Oxycone; whorl breadth to height ratio 0.43. Venter of phragmocone sharp, becoming progressively blunter on body chamber. Shell surface of phragmocone bears delicate prorsiradiate growth lines and striae on inner flank, strengthened into distant, low, concave ribs on outer flank; ribs lost on body chamber. Suture (Fig. 14.5) corroded, with entire saddles. Types. -Lectotype, here designated, is the original of Noetling, 1897, pl. 21, figs. 3, 3a, from the Maastrichtian of the '136s valley, near Khattan'; an unfigured paralectotype is from 'Mazar Drik', Baluchistan.

Discussion / Comments:

FATMI & Kennedy (1999):
Discussion-Libycoceras acutodorsatus has the shell morphology typical of Sphenodiscus (e.g., Zaborski, 1982, fig. 22), but the entire saddles are quite unlike those of that genus, more resembling those of Libycoceras, as indicated by Howarth (1965, p. 394). Howarth also noted that all other species of the genus are characterised by a stouter whorl section and lateral and ventrolateral tuberculation (e.g., Zaborski, 1982, figs. 4-13, 17-19).

Systematics:

40
Ordo Ammonoidea
  Subordo Ammonitina
   Superfamilia Acanthocerataceae
    Superfamilia Desmocerataceae
     Familia Pachydiscidae
      Familia Sphenodiscidae
       Genus Libycoceras
        Species Libycoceras acutodorsatus

Synonym list:

FATMI & Kennedy (1999):

1897 Sphenodiscus acutodorsatus Noetling. - Noetling : p.76 pl. 21, figs. 3, 3a

1904 Sphenodiscus acutodorsatus Noetling. - Douville : p.255 pl. 35, fig. 1

1965 Libycoceras acutodorsatus Noetling. - Howarth : p.394

1999 Libycoceras acutodorsatus Noetling. - FATMI & Kennedy : Figs. 10.1-10.3, 14.5

Stratigraphy - relative ages:

upper Maastrichtian: FATMI & Kennedy (1999)

References:

Noetling,F.. (1897):
Fauna of the upper Cretaceous (Maastrichtien) beds of the Mari Hills. . Palaeontologia indica Vol. 16(1(3)) p. 1-79

Douville,H.. (1904):
Mollusques fossiles.
In: Mission Scientifique en Perse, Etudes geologiques, Partie IV Vol. 3 Eds: Morgan, d.J.. p. 191-380

Howarth,M.K.. (1965):
Cretaceous ammonites and nautiloids from Angola . Bull. Br. Mus. nat. Hist. (Geol.) Vol. 10 p. 335-415

FATMI,A.N.. and Kennedy,W.J.. (1999):
Maastrichtian ammonites from Balochistan, Pakistan. . Journal of Paleontology Vol. 73(4) p. 641-662

Anonymous: Unedited TaxonConcept data

This work is licensed under a Creative Commons Attribution 2.5 License.

Back to Search

Taxon relations
pdf
Ranking (experimental)