Ptychodus occidentalis
Leidy, 1868
Classification: Elasmobranchii incert. sedis Ptychodontidae
Reference of the original description
Notice of American species of Ptychodus. Proceedings of the Academy of Natural Sciences of Philadelphia, 20, 205–208
Notice of American species of Ptychodus. Proceedings of the Academy of Natural Sciences of Philadelphia, 20, 205–208
Synonyms / new combinations and misspellings
Ptychodus cf. occidentalis
Ptychodus cf. occidentalis
Images of types
Description:
Citation: Ptychodus occidentalis Leidy, 1868: In: Database of fossil elasmobranch teeth www.shark-references.com, World Wide Web electronic publication, Version 11/2024
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Ptychodus occidentalis Leidy, 1868, syntype, ANSP 1465, near Fort Hays, Kansas © Mike Everhart, Sternberg Museum of Natural History
Ptychodus occidentalis Leidy, 1868, syntype, ANSP 1465, near Fort Hays, Kansas © Mike Everhart, Sternberg Museum of Natural History
Description
Original description after Leidy (1868) p. 207 [1414]: Ptychodus occidentalis, n. s.
The Museum of the Academy contains a specimen consisting of the crown of a tooth of a species oi Ptychodus differing from any other previously known. It was obtained by Dr. John L. LeConte, in association with other remains of fishes, from an ash-colored rock of the Cretaceous series, a few miles east of Fort Hays, Kansas.
The tooth is remarkable, especially from the comparatively near approximation of its diameters, the width transversely and fore and aft and the height approaching one another more nearly than in any other species. The forepart of the crown is somewhat injured and the root is broken away. The transverse diameter of the crown at base is 14 lines: the fore and aft diameter has been about an inch: and the height is also an inch. In shape the crown is a blunt cone with the sides sloping evenly to the base and to the posterior sinus. The latter is a triangular concavity about twothirds of the breadth in height.
The direction and arrangement of the ridges of the crown are much like as in the European Ptychodus decurrens, but the principal ridges crossing the crown transversely are finer and the intervals much narrower, indeed the space occupied by a pair of ridges with their interval in P. decurrens would accommodate three ridges with a pair of intervals in P. occidentalis. Descending the sides of the cone the ridges branch as in P. Mortoni, and at the basal half of the crown form a reticulation much as in P. decurrens. At the back of the summit of the crown the principal ridges continue their transverse or parallel course until near the upper part of the. sinus, into which as they descend they are resolved into a fine reticulation. The fore-part of the crown is occupied by a reticulation formed by the descent, convergence and division of the more anterior principal ridges.
From the description it will be observed that the tooth holds an intermediate position in anatomical character to those of Ptychodus Mortoni, and P. decurrens.
Three small teeth, found by Dr. Le Conte in association with the latter, resemble, in their proportions and in the proportionate size and arrangement of the ridges of the crown, the teeth of P. decurrens, but perhaps may belong to the same species as the large tooth above described. The larger of the three specimens is perfect, but has the summit of its crown worn ott'. The crown measures 7 lines transversely, 6 lines fore and aft, and has been from 4 to 5 lines high. The root is 6 lines wide, 41/2 lines fore and aft, and 2 1/2 lines thick. Comparatively coarse ridges cross the crown transversely, curving forward laterally and ending in a marginal reticulation. Branching ridges descend in front from the foremost of the transverse ridges, and likewise end in a marginal reticulation. The sinus is occupied by a finer reticulation joined by fine ridges descending from the summit and sides of the crown. The smallest tooth, likewise perfect, has the crown 4 1/2 lines wide, 3 1/2 lines fore and aft, and 2 1/2 lines high.
Three additional specimens associated with the former ones, are the smallest teeth of Ptychodus I have seen, but I suspect that they belong to the same species. They are transversely ellipsoidal in outline at the base of the crown, and this appears as a low cone elevated at the inner third and with a broad expanding base. The sinus is situated at the inner posterior third. The surface of the crown is crossed with transverse ridges which form a narrow reticulation at the border. The largest of these small specimens is 3 1/2 lines transversely, 1 1/2 fore and aft, and | of a line high from the root. The smallest tooth is 2 1/2 lines wide, 1 1/2- fore and aft, and 1/2 a line from the root.
Original description after Leidy (1868) p. 207 [1414]: Ptychodus occidentalis, n. s.
The Museum of the Academy contains a specimen consisting of the crown of a tooth of a species oi Ptychodus differing from any other previously known. It was obtained by Dr. John L. LeConte, in association with other remains of fishes, from an ash-colored rock of the Cretaceous series, a few miles east of Fort Hays, Kansas.
The tooth is remarkable, especially from the comparatively near approximation of its diameters, the width transversely and fore and aft and the height approaching one another more nearly than in any other species. The forepart of the crown is somewhat injured and the root is broken away. The transverse diameter of the crown at base is 14 lines: the fore and aft diameter has been about an inch: and the height is also an inch. In shape the crown is a blunt cone with the sides sloping evenly to the base and to the posterior sinus. The latter is a triangular concavity about twothirds of the breadth in height.
The direction and arrangement of the ridges of the crown are much like as in the European Ptychodus decurrens, but the principal ridges crossing the crown transversely are finer and the intervals much narrower, indeed the space occupied by a pair of ridges with their interval in P. decurrens would accommodate three ridges with a pair of intervals in P. occidentalis. Descending the sides of the cone the ridges branch as in P. Mortoni, and at the basal half of the crown form a reticulation much as in P. decurrens. At the back of the summit of the crown the principal ridges continue their transverse or parallel course until near the upper part of the. sinus, into which as they descend they are resolved into a fine reticulation. The fore-part of the crown is occupied by a reticulation formed by the descent, convergence and division of the more anterior principal ridges.
From the description it will be observed that the tooth holds an intermediate position in anatomical character to those of Ptychodus Mortoni, and P. decurrens.
Three small teeth, found by Dr. Le Conte in association with the latter, resemble, in their proportions and in the proportionate size and arrangement of the ridges of the crown, the teeth of P. decurrens, but perhaps may belong to the same species as the large tooth above described. The larger of the three specimens is perfect, but has the summit of its crown worn ott'. The crown measures 7 lines transversely, 6 lines fore and aft, and has been from 4 to 5 lines high. The root is 6 lines wide, 41/2 lines fore and aft, and 2 1/2 lines thick. Comparatively coarse ridges cross the crown transversely, curving forward laterally and ending in a marginal reticulation. Branching ridges descend in front from the foremost of the transverse ridges, and likewise end in a marginal reticulation. The sinus is occupied by a finer reticulation joined by fine ridges descending from the summit and sides of the crown. The smallest tooth, likewise perfect, has the crown 4 1/2 lines wide, 3 1/2 lines fore and aft, and 2 1/2 lines high.
Three additional specimens associated with the former ones, are the smallest teeth of Ptychodus I have seen, but I suspect that they belong to the same species. They are transversely ellipsoidal in outline at the base of the crown, and this appears as a low cone elevated at the inner third and with a broad expanding base. The sinus is situated at the inner posterior third. The surface of the crown is crossed with transverse ridges which form a narrow reticulation at the border. The largest of these small specimens is 3 1/2 lines transversely, 1 1/2 fore and aft, and | of a line high from the root. The smallest tooth is 2 1/2 lines wide, 1 1/2- fore and aft, and 1/2 a line from the root.
Image gallery
References
Faszination Haie – Die Welt der fossilen und der lebenden Haie. Der Steinkern, 58, 1–116
Microvertebrate faunal assemblages of the Favel Formation (late Cenomanian-middle Turonian) of Manitoba, Canada. Peerj, 11, Article e15493
DOI: 10.7717/peerj.15493
Global impact and selectivity of the Cretaceous-Paleogene mass extinction among sharks, skates, and rays. Science, 379, 802–806
DOI: 10.1126/science.abn2080
Stratigraphic, Geographic, and Paleoecological Distribution of the Late Cretaceous Shark Genus Ptychodus within the Western Interior Seaway, North America. New Mexico Museum of Natural History and Science, Bulletin, 81, 1–94
A New Late Cretaceous Marine Vertebrate Assemblage from the Lincoln Limestone Member of the Greenhorn Limestone in Southeastern Colorado. Transactions of the Kansas Academy of Science, 115(3–4), 107–116
DOI: 10.1660/062.115.0303
Late Cretaceous Marine Fishes from the Upper Greenhorn Limestone in Southeastern Nebraska. Transactions of the Kansas Academy of Science, 116(1–2), 22–26
DOI: 10.1660/062.116.0104
Fossil vertebrates from the tropic shale (Upper cretaceous), southern Utah. In Titus, A.L., Loewen, M.A. (Eds.), At the Top of the Grand Staircaes, The Late Cretaceous of Southern Utah. Indiana University Press.
Late Cretaceous marine fishes from the Upper Greenhorn Limestone in southeastern Nebraska, USA [Abstract]. Journal of Vertebrate Paleontology, 32(Suppl. 1), 64
A selachian-dominated assemblage from the Upper Cretaceous (Cenomanian) Clay Mesa Member, Mancos Formation, Santa Fe County, NM. New Mexico Museum of Natural History and Science, Bulletin, 53, 386–392
Mid-Cenomanian vertebrate faunas of the WesternInterior Seaway of North America and their evolutionary, paleobiogeographical, and paleoecological implications. Palaeogeography, Palaeoclimatology, Palaeoecology, 295(1–2), 199–214
DOI: 10.1016/j.palaeo.2010.05.038
Partial Skull of Late Cretaceous Durophagous Shark, Ptychodus occidentalis (Elasmobranchii: Ptychodontidae), from Nebraska, U.S.A. Journal of Vertebrate Paleontology, 29(2), 336–349
DOI: 10.1671/039.029.0226
Low diversity selachian assemblage from the upper cretaceous Greenhorn Limestone, Socorro County, New Mexico. New Mexico Geological Society Guidebook, 60th Field Conference, Geology of the Chupadera Mesa Region: 311–314
Fossil fishes from the basal Greenhorn Limestone (Upper Cretaceous: late Cenomanian) in Russell County, Kansas. Fort Hays Studies, (Special Issue 2), 89–103
Systematic, stratigraphic, geographic, and paleoecological distribution of the Late Cretaceous shark genus Ptychodus within the Western Interior Seaway. Unpublished MS thesis, University of Texas, Dallas, 434 pp
Upper Cenomanian selachian assemblage from the Bridge Creek Member of the Mancos Shale, Socorro County, New Mexico [Abstract]. New Mexico Geological Society, Programm with abstracts: 38
Late Cretaceous selachian biostratigraphy in New Mexico. M.S. thesis: Albuquerque, University of New Mexico, 117 p.
Fossil marine vertebrates from the lowermost Greenhorn Limestone (Upper Cretaceous: Middle Cenomanian) in southeastern Colorado. Journal of Paleontology, 80(sp63), 1–45
DOI: 10.1666/0022-3360(2006)80[1:FMVFTL]2.0.CO;2
Cenomanian bonebed faunas from the northeastern margin, Western Interior seaway, Canada. New Mexico Museum of Natural History and Science, Bulletin, 35, 139–155
Fossil fishes from the lowermost Greenhorn Limestone (Upper Cretaceous: Middle Cenomanian) in southeastern Colorado [Abstract]. Geological Society of America Abstracts with Programs
Fossil selachians from the Belle Fourche Shale (Cretaceous, Cenomanian), Black Hills region of South Dakota and Wyoming. Mountain Geologist, 38(4), 181–192
Cretaceous elasmobranchs of the Greenhorn Formation (Middle Cenomanian-Middle Turonian), western South Dakota Proceedings of the 6th Fossil Resource Conference: National Park Service Geological Resource Division Technical Report NPS/NRGRD/ GRDTR01/01. p. 27–43 in V. L. Santucci and L. McClelland(eds.),
Fossil selachians from the Belle Fourche Shale (Cretaceous, Cenomanian), Black Hills region of South Dakota and Wyoming. Mountain Geologist, 38(4), 181–192
Upper Cretaceous Sharks and Rays from the Prokop Opencast Mine at Brezina Near Moravska Trebova. Acta Universitatis Palackianae Olmucensis, Geologica, 36, 51–61
The collector's guide to fossil sharks and rays from the Cretaceous of Texas. Before Time, Lewisville, 1993
Type and figured specimens of fossil vertebrates in the collection of the University of Kansas Museum of Natural History. Part I. Fossil Fishes. University of Kansas, Museum of Natural History, Miscellaneous Publication, 73: 1–53
Bibliography and catalogue of the fossil Vertebrata of North America. Bulletin of the United States Geological and Geographical Survey of the Territories, 179, 1–868
Cretaceous fishes. Selachians and Ptychodonts. University Geological Survey of Kansas, 6(2): 237–256, pl. 24–32.
Some fish teeth from the Kansas Cretaceous. Kansas University Quarterly, 9(1): 27–42, pl. 6–14.
The Vertebrata of the Cretaceous formations of the West. Report of the United States Geological Survey of the Territories, 2: 303 p., 67 pl.
Review of the Vertebrata of the Cretaceous period found west of the Mississippi River. Sec. I. On the mutual relations of the Cretaceous and Tertiary formations of the West. Sec. II. List of species of Vertebrata from the Cretaceous formations. Bulletin of the United States Geological and Geographical Survey of the Territories, 1(2), 3–48
Notice of American species of Ptychodus. Proceedings of the Academy of Natural Sciences of Philadelphia, 20, 205–208
Faszination Haie – Die Welt der fossilen und der lebenden Haie. Der Steinkern, 58, 1–116
Microvertebrate faunal assemblages of the Favel Formation (late Cenomanian-middle Turonian) of Manitoba, Canada. Peerj, 11, Article e15493
DOI: 10.7717/peerj.15493
Global impact and selectivity of the Cretaceous-Paleogene mass extinction among sharks, skates, and rays. Science, 379, 802–806
DOI: 10.1126/science.abn2080
Stratigraphic, Geographic, and Paleoecological Distribution of the Late Cretaceous Shark Genus Ptychodus within the Western Interior Seaway, North America. New Mexico Museum of Natural History and Science, Bulletin, 81, 1–94
A New Late Cretaceous Marine Vertebrate Assemblage from the Lincoln Limestone Member of the Greenhorn Limestone in Southeastern Colorado. Transactions of the Kansas Academy of Science, 115(3–4), 107–116
DOI: 10.1660/062.115.0303
Late Cretaceous Marine Fishes from the Upper Greenhorn Limestone in Southeastern Nebraska. Transactions of the Kansas Academy of Science, 116(1–2), 22–26
DOI: 10.1660/062.116.0104
Fossil vertebrates from the tropic shale (Upper cretaceous), southern Utah. In Titus, A.L., Loewen, M.A. (Eds.), At the Top of the Grand Staircaes, The Late Cretaceous of Southern Utah. Indiana University Press.
Late Cretaceous marine fishes from the Upper Greenhorn Limestone in southeastern Nebraska, USA [Abstract]. Journal of Vertebrate Paleontology, 32(Suppl. 1), 64
A selachian-dominated assemblage from the Upper Cretaceous (Cenomanian) Clay Mesa Member, Mancos Formation, Santa Fe County, NM. New Mexico Museum of Natural History and Science, Bulletin, 53, 386–392
Mid-Cenomanian vertebrate faunas of the WesternInterior Seaway of North America and their evolutionary, paleobiogeographical, and paleoecological implications. Palaeogeography, Palaeoclimatology, Palaeoecology, 295(1–2), 199–214
DOI: 10.1016/j.palaeo.2010.05.038
Partial Skull of Late Cretaceous Durophagous Shark, Ptychodus occidentalis (Elasmobranchii: Ptychodontidae), from Nebraska, U.S.A. Journal of Vertebrate Paleontology, 29(2), 336–349
DOI: 10.1671/039.029.0226
Low diversity selachian assemblage from the upper cretaceous Greenhorn Limestone, Socorro County, New Mexico. New Mexico Geological Society Guidebook, 60th Field Conference, Geology of the Chupadera Mesa Region: 311–314
Fossil fishes from the basal Greenhorn Limestone (Upper Cretaceous: late Cenomanian) in Russell County, Kansas. Fort Hays Studies, (Special Issue 2), 89–103
Systematic, stratigraphic, geographic, and paleoecological distribution of the Late Cretaceous shark genus Ptychodus within the Western Interior Seaway. Unpublished MS thesis, University of Texas, Dallas, 434 pp
Upper Cenomanian selachian assemblage from the Bridge Creek Member of the Mancos Shale, Socorro County, New Mexico [Abstract]. New Mexico Geological Society, Programm with abstracts: 38
Late Cretaceous selachian biostratigraphy in New Mexico. M.S. thesis: Albuquerque, University of New Mexico, 117 p.
Fossil marine vertebrates from the lowermost Greenhorn Limestone (Upper Cretaceous: Middle Cenomanian) in southeastern Colorado. Journal of Paleontology, 80(sp63), 1–45
DOI: 10.1666/0022-3360(2006)80[1:FMVFTL]2.0.CO;2
Cenomanian bonebed faunas from the northeastern margin, Western Interior seaway, Canada. New Mexico Museum of Natural History and Science, Bulletin, 35, 139–155
Fossil fishes from the lowermost Greenhorn Limestone (Upper Cretaceous: Middle Cenomanian) in southeastern Colorado [Abstract]. Geological Society of America Abstracts with Programs
Fossil selachians from the Belle Fourche Shale (Cretaceous, Cenomanian), Black Hills region of South Dakota and Wyoming. Mountain Geologist, 38(4), 181–192
Cretaceous elasmobranchs of the Greenhorn Formation (Middle Cenomanian-Middle Turonian), western South Dakota Proceedings of the 6th Fossil Resource Conference: National Park Service Geological Resource Division Technical Report NPS/NRGRD/ GRDTR01/01. p. 27–43 in V. L. Santucci and L. McClelland(eds.),
Fossil selachians from the Belle Fourche Shale (Cretaceous, Cenomanian), Black Hills region of South Dakota and Wyoming. Mountain Geologist, 38(4), 181–192
Upper Cretaceous Sharks and Rays from the Prokop Opencast Mine at Brezina Near Moravska Trebova. Acta Universitatis Palackianae Olmucensis, Geologica, 36, 51–61
The collector's guide to fossil sharks and rays from the Cretaceous of Texas. Before Time, Lewisville, 1993
Type and figured specimens of fossil vertebrates in the collection of the University of Kansas Museum of Natural History. Part I. Fossil Fishes. University of Kansas, Museum of Natural History, Miscellaneous Publication, 73: 1–53
Bibliography and catalogue of the fossil Vertebrata of North America. Bulletin of the United States Geological and Geographical Survey of the Territories, 179, 1–868
Cretaceous fishes. Selachians and Ptychodonts. University Geological Survey of Kansas, 6(2): 237–256, pl. 24–32.
Some fish teeth from the Kansas Cretaceous. Kansas University Quarterly, 9(1): 27–42, pl. 6–14.
The Vertebrata of the Cretaceous formations of the West. Report of the United States Geological Survey of the Territories, 2: 303 p., 67 pl.
Review of the Vertebrata of the Cretaceous period found west of the Mississippi River. Sec. I. On the mutual relations of the Cretaceous and Tertiary formations of the West. Sec. II. List of species of Vertebrata from the Cretaceous formations. Bulletin of the United States Geological and Geographical Survey of the Territories, 1(2), 3–48
Notice of American species of Ptychodus. Proceedings of the Academy of Natural Sciences of Philadelphia, 20, 205–208
