Sphenodiscus spp.

Landman, Neil H., 2004, Cephalopods From The Cretaceous / Tertiary Boundary Interval On The Atlantic Coastal Plain, With A Description Of The Highest Ammonite Zones In North America. Part 2. Northeastern Monmouth County, New Jersey, Bulletin of the American Museum of Natural History 2004 (287), pp. 1-107 : 55

publication ID

https://doi.org/ 10.1206/0003-0090(2004)287<0001:CFTTBI>2.0.CO;2

persistent identifier

https://treatment.plazi.org/id/B01187C6-7843-FB19-FEBF-FE152FFCD9A9

treatment provided by

Felipe

scientific name

Sphenodiscus spp.
status

 

Sphenodiscus spp. Figure 26 View Fig

MATERIAL: There are four specimens that are too fragmentary for specific determination: AMNH 47119 About AMNH , 47122 About AMNH , and 50382 from the New Egypt / Hornerstown formational contact, AMNH loc. 3345, Parkers Creek , near Eatontown , Monmouth County, New Jersey ; and AMNH 47170 About AMNH from the upper part of the New Egypt Formation , approximately 2–2.5 m below the base of the Hornerstown Formation , AMNH loc. 3350, a tributary of Hockhockson Brook , 0.7 km southwest of the intersection of Water Street and Tinton Avenue , Tinton Falls , Monmouth County, New Jersey .

DESCRIPTION: AMNH 47119 (fig. 26) and 47122 (not illustrated) are pieces of phragmocones. Both specimens are badly worn with etched sutures. Neither specimen bears any trace of nodes. AMNH 47119 consists of two fragments with a preserved whorl height of 86 mm. It is broken in half and shows an oxyconic whorl section. Part of the left side is covered with botryoidal swellings, possibly due to a parasitic infestation or more probably a diagenetic phenomenon. AMNH 47122 consists of four pieces, the largest of which has a preserved whorl height of 77 mm.

AMNH 47170 is a fragment of an internal mold of a large body chamber with most of the venter missing (not illustrated); it is 230 mm in maximum length. The whorl section is oxyconic with a sharply rounded venter. The specimen is poorly preserved but exhibits a weak swelling on the outer flanks.

DISCUSSION: These specimens are too fragmentary for specific identification. AMNH 47170 shows a weak swelling on the outer flanks indicating that it may be related to Sphenodiscus pleurisepta . The other speci­ mens do not show any evidence of nodes, suggesting kinship with S. lobatus .

OCCURRENCE: These specimens occur at the New Egypt /Hornerstown formational contact, AMNH loc. 3345, Parkers Creek, near Eatontown, and 2–2.5 m below the base of the Hornerstown Formation, AMNH loc. 3350, near Tinton Falls, Monmouth County, New Jersey.

SUBORDER ANCYLOCERATINA WIEDMANN, 1966

SUPERFAMILY TURRILITACEAE GILL, 1871 View in CoL

FAMILY BACULITIDAE GILL, 1871 View in CoL [= EUBACULITINAE BRUNNSCHWEILER, 1966 ]

AMNH

American Museum of Natural History

Kingdom

Animalia

Phylum

Mollusca

Class

Cephalopoda

Order

Ammonoidea

Family

Sphenodiscidae

Genus

Sphenodiscus

Loc

Sphenodiscus spp.

Landman, Neil H. 2004
2004
Loc

ANCYLOCERATINA

WIEDMANN 1966
1966
Loc

EUBACULITINAE

BRUNNSCHWEILER 1966
1966
Loc

TURRILITACEAE

GILL 1871
1871
Loc

BACULITIDAE

GILL 1871
1871
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