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Phylloptychoceras sipho Forbes 1846 from: Kennedy, W.J..Henderson, R.A.. (1992): Heteromorph ammonites from the Upper Maastrichtian of Pondicherry, south India . Palaeontology Vol. 35 p. 693-731
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Species Phylloptychoceras sipho Forbes 1846

Diagnosis / Definition:
Kennedy & Henderson (1992):
DESCRIPTION.- The earliest development stages are shown by BMNH C51155 and 51160 (Pl. 5, figs. 18, 24), which consist of minute subparallel shafts in tight contact, linked by narrowly curved sections, where shafts are separated by tear-shaped opening; the shell is smooth, but for prorsiradiate growth lines, BMNH C51161 is a similar fragment (Pl. 5, fig. 19), but much larger, BMNH C51154 (Pl. 5, fig. 23) is the same size and shape as BMNH C51161, with a circular cross section and feeble ornament of low, broad, feebly prorsiradiate ribs, and a single constriction. If, as seems likely, these are correctly interpreted as successive growth stages of the same form (rather than of macro- and microconchs), then the shell consisted of four closely adpressed subparallel shafts, the first three and part of the fourth being septate. The lectotype (Pl. 5, fig. 31-32) is the best-preserved of the adult specimens, and is 107mm long. The whorl section is subcircular, slightly compressed at the adapical end, and consists of a slightly curved shaft and short recurved crozier. The whorl breadth to height ratio is 0.83 at the mid-point of the shaft, but becomes markedly depressed and reniform on the final curved sector. Ornament on the shaft is of low, broad, distant, round ribs; the rib index is two. Ribs are weak and transverse on the dorsum, straight and feebly prorsiradiate on the flanks, and strong and transverse across the venter. The ribs weaken, narrow and crowd on the final section of the shaft and the initial part of the hook, disappearing altogether on the final section of the hook, where they are replaced by crowded growth lines. The final, adult aperture appears to have been flared and trumpet-shaped, as suggested by BMNH C41503. Suture (Text-fig. 2D)greatly simplified with narrow-stemmed, bifid saddles with only minor identations; lobes have narrow necks, with splayed bifid lateral elements and a larger median element, entire in L and U.
Ward & Kennedy (1993):
Description and discussion. - The Biscay examples are juveniles consisting of two parallel shafts in close proximity, but not in contact, linked by a narrow curved portion. The composite mold is smooth, as in paralectotypes of comparable size (e.g., BMNH C5 1 155, the original of Forbes, 1846, P1. 1 1, fig. 5c, f, C5 1 160; Figure 18.8). The holotype of Neocyrtochilus bryani Anderson, 1958 (p. 189, P1. 72, fig. 5) is of comparable size, nearly smooth, and a possible synonym.
Discussion / Comments:
Kennedy & Henderson (1992):
TYPES.- Lectotype, by the subsequent designation of Howarth (1965, p. 386) is BMNH C51153, the original of Forbes (1846, pl. 11, fig. 5a), GSC R10504; paralectotype BMNH C51154 is the original of Forbes (1846, pl. 11, figs. 5b, e), GSC R10506; paralectotype BMNH C51155 is the original of Forbes (1846, pl. 11, figs. 5c, f), GSC R10507; paralectotype BMNH C41502 is probably the original of Forbes (1846, pl. 11, fig. 5d); unfigured paralectotypes are BMNH C41503, C51156-51161, all from the Valudavur Formation of Pondicherry, south India (ex Kaye and Cunliffe Collection). Topotypes are BMNH C3521, and 24199. The holotype of Hamites constrictus d’Orbigny, 1847 (pl. 3, figs. 7-8), is MNHP R982 (Pl. 5, figs. 27-28), also a topotype of P. sipho. DISCUSSION.- Hamites constrictus d'Orbigny, 1847a (pl. 3, fig. 7-8) is based on a Pondicherry specimen of P. sipho (Pl. 5, figs. 27-28). The holotype of Neocyrtochilus bryani Anderson, 1958 (p. 189, pl. 72, fig. 5) is based on a small smooth form with ptychoceratid coiling like the early stages of the present species, and said, by Anderson, to be of Maastrichtian age; it is a possible synonym, as is the Phylloptychoceras sp. of Stinnisbeck (1986, p. 200, pl. 15, fig. 3; text-fig. 22), from the Maastrichtian of Chile. OCCURRENCE.- Maastrichtian of south India and, possibly, Chile and California, and the Biscay region of France and Spain.
Ward & Kennedy (1993):
Type. - Lectotype is BMNH C5 1 153, the original of Forbes, 1846, P1. 1 1, fig. 5a, designated by Howarth, 1965, p. 386; from the Valudavur Formation of Pondichemy, south India. Occurrence. - In the Biscay region this taxon is restricted to Member 111 (upper Maastrichtian). The types are from the upper Maastrichtian of south India, and if Neocyrtochilus bryani is a synonym, the geographic range extends to California.
Synonym list:
Kennedy & Henderson (1992):
1846 Ptychoceras sipho Forbes. - Forbes : p.118 pl. 11; fig. 5
1847 Hamites constrictus d'Orbigny. - d'Orbigny : pl. 3; fig. 7-8
1850 Ptychoceras sipho Forbes. - d'Orbigny : p.215
1850 Hamites constrictus d'Orbigny. - d'Orbigny : p.215
1866 Ptychoceras sipho Forbes. - Stoliczka : p.194 pl. 90; fig. 5-9
1895 Hamites (Ptychoceras) sp. sipho Forbes. - Kossmat : 150(54)
1953 Phylloptychoceras sipho Forbes. - Spath : p.19 pl. 11; fig. 7
? 1958 Neocyrtochilus bryani Anderson. - Anderson : p.189 pl. 72; fig. 5
1965 Phylloptychoceras sipho Forbes. - Howarth : p.386 pl. 11; fig. 1
1970 Phylloptychoceras sipho Forbes. - Henderson : text-fig. 7b
1977 Phylloptychoceras sipho Forbes. - Kennedy : text-fig. 3120
? 1986 Phylloptychoceras sp. . - Stinnesbeck : p.200 pl. 15, fig. 3; text-fig. 22
1989 Phylloptychoceras Spath. - Kennedy : text-fig. 18f
1992 Phylloptychoceras sipho Forbes. - Kennedy & Henderson : p. 711, 715, 703 pl. 4, fig. 5; pl. 5, fig. 18-32; text-fig. 2D
Ward & Kennedy (1993):
1846 Ptychoceras sipho Forbes. - Forbes : p.118 pl. 11; fig. 5
1866 Ptychoceras sipho Forbes. - Stoliczka : p.194 pl. 90; fig. 5-9
1895 Ptychoceras sipho Forbes. - Kossmat : 150 (54)
1925 Ptychoceras sipho Forbes. - Diener : p.78
1953 Phylloptychoceras sipho Forbes. - Spath : p.19 pl. 11; fig. 7
1965 Phylloptychoceras sipho Forbes. - Howarth : p.386 pl. 11; fig. 1
1993 Phylloptychoceras sipho Forbes. - Ward & Kennedy : p. 19, 50 fig. 18.8, 43.3, 43.4
Stratigraphy - relative ages:
upper Maastrichtian: Ward & Kennedy (1993)
Maastrichtian: Kennedy & Henderson (1992)

Forbes,E.. (1846):
Report on the Cretaceous fossil invertebrates from southern India, collected by Mr. Kaye and Mr. Cunliffe . Transactions of the Geological Society of London Vol. 2(7) p. 97–174

d'Orbigny,A. (1847):
Paléontologie, Pls. 1-6 (Geologie Pls. 4-9).
In: M. de Dumont D'Urville, 1846-1 854, Voyage au Pole Sud et dans I'Oceanie sur les corvelles L'Astrolabe et la Zelée pendant les années 1837- 1838-1839-1840 sous le commandément de M. Dumont D'Urville Capitaine du Vaisseau. Pls. 1-9 Eds: Baudry, G..

d'Orbigny,A. (1850):
Prodrome de Paléontologie. Stratigraphique universelle des animaux mollusques & rayonnés faisant suitre au cours élémentaire de paléontologie et de géologie stratigraphique. , Cours Élémentaire de Paléontologie et de Géologie Stratigraphiques Vol. 2

Stoliczka,F.. (1866):
The fossil Cephalopoda of the Cretaceous rocks of southern India. Ammonitidae with revision of the Nautilidae etc. . Memoirs of the Geological Survey of India, (l), Palaeontologica Indica10-13 p. 155-216

Kossmat,F.. (1895):
Untersuchungen,über die Südindische Kreideformation. Beitrage zur Palaontologie Osterreich-Ungarns und des Orients . Vol. 9 p. 97-203 (1-107)

Kossmat,F.. (1895):
Untersuchungen über die Südindische Kreideformation. Erster Theil . Beiträge zur Paläontologie Österreich-Ungarns und des Orient Vol. 9 p. 97-203

Diener,C.. (1925):
Ammonoidea neocretacea . Fossilium Cat, (1: Animalia) Vol. 29 p. 244 pp.

Spath,L.F.. (1953):
The upper Cretaceous cephalopod fauna of Graham Land . Scientific Reports of the Falkland Islands Survey Department Vol. 3 p. 60

Anderson,F.M.. (1958):
Upper Cretaceous of the Pacific Coast: , 71, 378 p. . New York, Geological Society of America Memoir Vol. 71 p. 378

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

Henderson,R.A.. (1970):
Ammonoidea from the Mata Series (Santonian - Maastrichtian) of New Zealand . Special Papers in Palaeontology Vol. 6 p. 1-82

Kennedy,W.J.. (1977):
Ammonite evolution.
In: Patterns of Evolution Eds: Hallam, A.. p. 251-330

Stinnesbeck,W.. (1986):
Zu den faunistischen und palökologischen Verhältnissen in der Quriquina Formation (Maastrichtium)Zentral-Chiles . Palaeontographica A194((4-6)) p. 99-237

Kennedy,W.J.. (1989):
Thoughts on the evolution and extinction of Cretaceous ammonites . Procedings of the Geologists Association Vol. 100 p. 251-279

Kennedy,W.J.. and Henderson,R.A.. (1992):
Heteromorph ammonites from the Upper Maastrichtian of Pondicherry, south India . Palaeontology Vol. 35 p. 693-731

Ward,P.D.. and Kennedy,W.J.. (1993):
Maastrichtian Ammonites from the Biscay Region (France, Spain) . Memoir (The Paleontological Society), Journal of Paleontology34 (Supplement to Vol. 67)(5) p. 1-58

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