TaxonConcept: Coahuilites sheltoni Böse 1928 from: Ifrim, C..Stinnesbeck, W..Schafhauser, A.. (2005): Maastrichtian shallow-water ammonites of northeastern Mexico . Revista Mexicana de Ciencias Geológicas Vol. 22(1) p. 48-64

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Coahuilites sheltoni Böse 1928 from: Ifrim, C..Stinnesbeck, W..Schafhauser, A.. (2005): Maastrichtian shallow-water ammonites of northeastern Mexico . Revista Mexicana de Ciencias Geológicas Vol. 22(1) p. 48-64

Anonymous: Unedited TaxonConcept data

Notice: This catalogue page may contain unedited data.

Species Coahuilites sheltoni Böse 1928


[1]


[2]

[1] 9a-c Ifrim et al. (2005) [2] 5f-g Ifrim et al. (2005)

Diagnosis / Definition:

Ifrim et al. (2005):
Description: The shell is involute and compressed. The steep umbilical wall bends narrowly into subparallel flanks. When juvenile, ventrolateral shoulders are widely rounded and the venter fastigiate, whereas during later ontogenetic stages ventrolateral shoulders are more narrowly rounded, and the venter is flattened. The greatest breadth is at midflank. There are seven to eight tubercles at mid-flank which are strong and slightly bullate. They give rise to low, flat, falcoid ribs which link the inner tubercles to an outer row of strong, conical tubercles on the ventrolateral shoulders. The venter is smooth. The suture line is moderately incised and becomes more simple towards the umbilicus. The broad E/L is moderately incised, and subdivided by two adventive lobes. L/U2 with minor incision. Ventralmost saddles of auxiliaries are moderately incised, dorsal ones are entire.
Cobban & Kennedy (1995):
DESCRIPTION.- USNM 463116, half a whorl of phragmocone 55 mm in diameter, is very involute with small, shallow umbilicus. Whorl section compressed with whorl breadth to height ratio 0.5 in intercostal section, the greatest breadth below midflank. Umbilical shoulder narrowly rounded, inner flanks slightly concave, midflank region feebly convex, outer flanks flattened, venter fastigiate. Five large, slightly bullate tubercles at midflank give rise to pairs of low, flat, falcoid ribs that link to blunt, conical ventrolateral tubercles. Venter smooth. USNM 463117 is somewhat larger fragment with whorl height of 38 mm. Suture has broad E/L split by adventive lobe of moderate width. Ventral part of E/L moderately incised, dorsal part less so. L/U, has minor incisions; ventral auxiliary saddles on umbilical lobe have trifid terminations succeeded by bifid terminations, the dorsalmost saddles being entire.

Discussion / Comments:

Ifrim et al. (2005):
Type: The holotype, by original designation, is the original of Böse, 1928, pl. 13, fig. 7. It comes from the Escondido Formation, 5 km south of Alamo Viejo near Villa de Juárez, Coahuila, Mexico. Material: One specimen from the Potrerillos Formation near Mina, N.L., one from Saltillo, Coahuila, two fragments from basal middle member of the Cárdenas Formation at the railway section east of Cárdenas. Occurrence: Where properly dated, the species is Maastrichtian in age. Records are from Mississippi and Alabama (Cobban and Kennedy, 1995), the Escondido Formation of northern Mexico and Trans-Pecos, Texas (Böse, 1928), the Western Interior of Colorado and Wyoming (Hoploscaphites birkelundi and Baculites clinolobatus zone; Landman and Cobban, 2003), and now from the Cárdenas and Potrerillos Formations of northeastern Mexico. Discussion: We agree with Cooper (1970), and Cobban and Kennedy (1995) and regard C. orynskii and C. cavinsi, also designated by Böse (1928), as synonyms of C. sheltoni.
Cobban & Kennedy (1995):
TYPE.- Holotype, by original designation, is the original of Bose, 1928, plate 13, figure 7, from the Escondido Formation 5 km south of Alamo Viejo in the region of Villa de Juarez, Coahuila, Mexico. NAME OF SPECIES.- We regard the three species of Coahuilites described by Bose (1928) as conspecific, as did Cooper (1970). As first revising authors we select the name sheltoni for the species. MATERIAL.- Two specimens, USNM 463116, 463117. DISCUSSION.- The studv of numerous Coahuilites from the Escondido Formation in Trans-Pecos Texas and northern Mexico has convinced the authors of the correctness of Cooper's (1970) conclusion that the three species described by Bose (1928), C. sheltoni, C. orynskii, and C. cavinsi are synonyms. The subparallel flanks, coarse ornament, and fastigiate venter, together with the broadening and flattening on the adult body chamber, serve to distinguish Coahuilites sheltoni from the other sphenodiscids present in the Prairie Bluff Chalk. OCCURRENCE.- Maastrichtian, Prairie Bluff Chalk at localities 21 and 40. The species is common in Escondido Formation in Trans-Pecos Texas and northern Mexico (see Cooper, 1970, for details). In the Western Interior, the species occurs in the zone of Hoploscaphites birkelundi in the Fox Hills Sandstone of Colorado and Wyoming.

Systematics:

36
Ordo Ammonoidea
  Subordo Ammonitina
   Superfamilia Acanthocerataceae
    Familia Sphenodiscidae
     Subfamilia Sphenodiscinae
      Genus Coahuilites
       Species Coahuilites sheltoni

46
  Ordo Ammonoidea
   Subordo Lytoceratina
    Superfamilia Acanthocerataceae
     Familia Sphenodiscidae
      Genus Coahuilites
       Species Coahuilites sheltoni

Synonym list:

Ifrim et al. (2005):

1928 Coahuilites sheltoni Böse. - Böse : p.283 pl. 13, figs. 4-11

1928 Coahuilites orynskii Böse. - Böse : p.287 pl. 14, figs 1-3

1928 Coahuilites cavinsi Böse. - Böse : p.290 pl. 14, figs. 4-8

1977 Coahuilites sheltoni Böse. - Wolleben : p.390 pl. 3, fig. 20

1995 Coahuilites sheltoni Böse. - Cobban & Kennedy : p.12 figs. 2.8-2.9,7.1-8.3 (with full synonymy)

1996 Coahuilites sheltoni Böse. - Kennedy et al. : p.6 figs. 2,3,4b

2003 Coahuilites sheltoni Böse. - Landman & Cobban : p.13 text-figs. 7-10

2005 Coahuilites sheltoni Böse. - Ifrim et al. : 56, 61 figs. 5f-g,8e-g,k-m,9a-c

Cobban & Kennedy (1995):

1928 Coahuilites sheltoni Böse. - Böse : p.283 pl. 13; fig. 4-11

1928 Coahuilites orynskii Böse. - Böse : p.287 pl. 14; fig. 1-3

1928 Coahuilites cavinsi Böse. - Böse : p.290 pl. 14; fig. 4-8

1952 Coahuilites sheltoni Böse. - Basse : p.601 fig. 11

1957 Coahuilites sheltoni Böse. - Wright : p.437 fig. 533 (2)

1965 Coahuilites sp. . - SCOTT & Cobban :

1975 Coahuilites sp. . - SCOTT & Cobban :

1986 Coahuilites sp. . - SCOTT & Cobban :

1995 Coahuilites sheltoni Böse. - Cobban & Kennedy : p. 2, 10, 11 fig. 2.8, 2.9, 7.1, 8.1-8.3

Stratigraphy - relative ages:

Maastrichtian: Ifrim et al. (2005)
Maastrichtian: Cobban & Kennedy (1995)

References:

Böse,E.. (1928):
Cretaceous ammonites from Texas and northern Mexico . University of Texas Bulletin Vol. 2748 p. 143–357

Basse,E.. (1952):
Classe des Cephalopodes.
In: Traite de paleontologie Vol. 2 Eds: Piveteau, J.. p. 461-488

Wright,C.W.. (1957):
Family Sphenodiscidae Hyatt, 1900.
In: Treatise on Invertebrate Paleontology, Part L, Mollusca 4 Eds: Moore, R.C.. p. L437

SCOTT,G.R.. and Cobban,W.A.. (1965):
Geologic and biostratigraphic map of the Pierre Shale between Jarre Creek and Loveland, Colorado . U.S. Geological Survey Miscellaneous Geologic Investigations, Map 1-439, scale 1:48,000, separate text

SCOTT,G.R.. and Cobban,W.A.. (1975):
Geologic and biostratigraphic map of the Pierre Shale in the Canon City-Florence basin and the Twelvemile Park area, south-central Colorado . U.S. Geological Survey Miscellaneous Investigations Series Map, 1-937, scale 1:48,000, separate text

Wolleben,J.A.. (1977):
Paleontology of the Difunta Group (Upper Cretacous– Tertiary) in northeastern Mexico . Journal of Paleontology Vol. 51(2) p. 373–398

SCOTT,G.R.. and Cobban,W.A.. (1986):
Geologic, biostratigraphic and structure map of the Pierre Shale between Loveland and Round Butte, Colorado . U.S. Geological Survey Miscellaneous Investigations Series Map, 1- 1700, scale 1 :50,000, separate text

Cobban,W.A.. and Kennedy,W.J.. (1995):
Maastrichtian ammonites chiefly from the Prairie Bluff Chalk in Alabama and Mississippi . Journal of Paleontology Vol. 69(5) p. 1-40

Kennedy,W.J..; Landman,N.H.. and Cobban,W.A.. (1996):
The Maastrichtian ammonites Coahuilites sheltoni Böse, 1928, and Sphenodiscus pleurisepta (Conrad, 1857), from the uppermost Pierre Shale and basal Fox Hills Formation of Colorado and Wyoming . American Museum Novitates Vol. 3186 p. 1–14

Landman,N.H.. and Cobban,W.A.. (2003):
Ammonites from the upper part of the Pierre Shale and Fox Hills Formation of Colorado . American Museum Novitates Vol. 3388 p. 1–45

Ifrim,C..; Stinnesbeck,W.. and Schafhauser,A.. (2005):
Maastrichtian shallow-water ammonites of northeastern Mexico . Revista Mexicana de Ciencias Geológicas Vol. 22(1) p. 48-64

Anonymous: Unedited TaxonConcept data

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