Cretalamna borealis ( Priem, 1897 )

Siversson, Mikael, Lindgren, Johan, Newbrey, Michael G., Cederström, Peter & Cook, Todd D., 2015, Cenomanian-Campanian (Late Cretaceous) mid-palaeolatitude sharks of Cretalamna appendiculata type, Acta Palaeontologica Polonica 60 (2), pp. 339-384 : 353-356

publication ID

https://doi.org/ 10.4202/app.2012.0137

persistent identifier

https://treatment.plazi.org/id/B63E4546-432A-FF87-FF74-FE946AB75BFD

treatment provided by

Felipe

scientific name

Cretalamna borealis ( Priem, 1897 )
status

 

Cretalamna borealis ( Priem, 1897)

Figs. 9 View Fig , 10 View Fig .

1897 Lamna appendiculata (Agassiz, 1843) [partim]; Priem 1897: 40, pl. 1: 4.

1897 Lamna borealis Priem, 1897 ; Priem 1897: 41, pl. 1: 9.

1977 Cretolamna appendiculata var. pachyrhiza Herman, 1977 [partim]; Herman 1977: 210, pl. 9: 3a–d (non fig. 3e [ C. sarcoportheta sp. nov.], 3f, g [undescribed Cretalamna and/or Otodus ex gr. obliquus ]).

1980 Cretolamna borealis ( Priem, 1897) ; Glikman 1980: pl. 10: 12, pl. 21: 1–5.

1983 Cretolamna appendiculata pachyrhiza Herman, 1977 ; Lauginiger and Hartstein 1983: 31, pl. 2: 11–14.

1992 Cretolamna appendiculata (Agassiz, 1843) [partim]; Siverson 1992a: 528, pl. 1: 5–8 (non figs. 1–4, 9–11 [ Cretalamna sarcoportheta sp. nov.]).

2005 Cretolamna sp. ; Vullo 2005: 620, fig. 4S, T.

Lectotype: An upper lateroposterior tooth, illustrated by Priem (1897:

pl. 1: 9); designated herein.

Type horizon: Unknown horizon within the latest early to middle late

Campanian, Late Cretaceous (see Christensen 1986).

Type locality: Köpinge Sandstone, Scania, Sweden.

Material.—Eleven teeth from Åsen (LO 6349t, 11135t – 11142t, 11350t, WAM 13.5.22), two teeth from Ugnsmunnarna (WAM 13.5.20, 21), and one tooth from Ignaberga (LO 6350t), Kristianstad Basin, southern Sweden (latest early Campanian).An upper lateroposterior tooth of C. borealis (LO 11351t) from the older, earliest early Campanian Gonioteuthis granulataquadrata Zone (conglomerate C, Ullstorp 1 quarry; Lindgren et al. 2007: 930) is also included for comparative purpose as it represents a small, juvenile tooth, demonstrating the difference in cusp width between teeth of comparable size of C. borealis and the dentally similar C. gertericorum sp. nov.

Emended diagnosis.—Anterior teeth elongated and flanked by pair of relatively small, commonly rounded and strongly divergent cusplets. Labial face of cusp almost as convex as lingual face in most lateroposterior teeth. Large, vertical folds commonly present in the basal part of the labial face of the cusp in lateroposterior teeth. Cusplets large on lateroposterior teeth and typically with convex inner edge and concave outer edge. Root rectangular and symmetrical with a small but relatively well demarcated protuberance in basal view in most lateroposterior teeth.

Description.— First upper anterior tooth file: One tooth is referred to the first upper right anterior file ( Fig. 9A View Fig ). As preserved it measures 32 mm in height. Both tips of the root lobes are damaged, resulting in a reduction of the tooth height by an estimated 1–2 mm. The cusp is, as is typical for teeth of this species found in near-shore strata of the Fennoscandian Shield, heavily worn from prey manipulation, resulting in a further reduction of the original height by an estimated 5–6 mm. The original height is thus an estimated 38–40 mm. The tall cusp is slightly distally curved. Its labial base is flush with the labial face of the root ( Fig. 9A View Fig 3 View Fig ). Both cusplets have a rounded, poorly defined apex and are divergent, especially the mesial one. The basal edge of the massive root is tightly curved. Both elongated lobes are labiolingually compressed. The root is rather symmetrical in labial/lingual views but asymmetrical in basal view, with a more compressed distal lobe.

Second upper anterior tooth file: Three teeth are referred to this file. The better preserved ones are illustrated and described. The larger right tooth ( Fig. 9B View Fig ) measures 32.5 mm in height, whereas the slightly smaller, left tooth ( Fig. 9C View Fig ) measures 30 mm in height. The latter has a somewhat worn apex and would have been about 1 mm taller originally. The left tooth is virtually complete whereas the larger right tooth is missing the mesial cusplet and part of the lingual protuberance of the root. In profile view, both teeth exhibit a slightly lingually curved cusp ( Fig. 9B View Fig 3 View Fig , C 2 View Fig ). The cusplets are divergent on both teeth and the cusp is somewhat distally inclined with a very slightly recurved apex. The root is asymmetrical with a longer mesial lobe. The well demarcated lingual protuberance of the root occupies a rather small area at the centre of the root’s lingual face.

Third upper anterior tooth file: There is no A3 available with the root preserved intact amongst the teeth from the informal Belemnellocamax mammillatus zone of the Kristianstad Basin. However, a poorly preserved tooth from the Ugnsmunnarna site (WAM 13.5.20, estimated original height 30 mm) features a relatively broad cusp, recurved in labial/lingual views and labially curved in profile view (similar to the cusp of the A 3 in C. ewelli sp. nov.; Fig. 12E). The tooth is not illustrated herein because of the very poor root preservation. Several additional teeth of C. borealis from Ugnsmunnarna (Peter Cederström collection) are likewise poorly preserved, an inconvenient fact given that the species appears to be relatively common at this site. We have seen photographs of a well-preserved A3 tooth (private collection) of C. borealis from the Offaster pilula Zone, Beauval quarry, northern France, displaying a cusp comparable to that of the tooth from Ugnsmunnarna and an asymmetrical root with the mesial lobe longer and narrower than the distal lobe (very similar to that of the A 3 in K. gunsoni ; Fig. 23C).

Upper lateroposterior tooth files: Anteriorly situated upper lateroposterior teeth have a triangular cusp, slightly distally inclined in labial/lingual views and straight in profile view. The root is markedly asymmetrical with a short, angular and broad distal lobe and a more elongated and acute mesial lobe (WAM 13.5.22). The median indentation of the basal edge of the root is V-shaped. More posteriorly situated teeth have a distally curved cusp ( Fig. 9D, E View Fig ). The lateral margins of the lobes of the root are typically vertical ( Fig. 9E View Fig 1 View Fig ). The lateral cusplets are large and most have a convex inner cutting edge and a concave outer edge ( Fig. 9E View Fig 3 View Fig ). The labial face of the cusp may have strong vertical wrinkles (LO 11139t). Commissural teeth are moderately elongated in a mesiodistal direction and have a strongly distally curved cusp (LO 11140t).

3

4

1

2

3

1

First lower anterior tooth file:A well preserved, 32.5 mm high tooth has features typical for the first lower anterior file in modern macrophagous lamniform sharks and is therefore assigned to this tooth-position ( Fig. 10A View Fig ). The cusp is almost perfectly straight in labial/lingual views and rather thick compared to the cusp on the two illustrated second upper anterior teeth. In profile view the cusp is markedly lingually curved. The cusplets are sub-triangular, divergent and have a blunt apex. The root is robust and nearly symmetrical with rather acute lobes. The lingual protuberance of the root is broad in basal view.

Lower lateroposterior tooth files: Teeth assigned to the inferred lower lateroposterior hollow differ from upper lateroposterior teeth in having a cusp that is more upright and more-or-less lingually curved in profile view. Like in the upper jaw, some lower lateroposterior teeth have coarse, vertical wrinkles in the lower part of the labial face of the cusp (WAM 13.5.21).

Remarks.—Teeth of C. borealis most closely resemble those of the other two species referred herein to the C. borealis group; C. gertericorum sp. nov. and C. ewelli sp. nov. This species group is characterised by the elongated anterior teeth, an A 3 type with a cusp that is recurved in labial/lingual views ( Fig. 12E 1 View Fig ) and labially curved in profile view ( Fig. 12E 2 View Fig ), strongly lingually curved lower anterior teeth in profile view ( Figs. 10A View Fig 4 View Fig , 11F View Fig 2 View Fig ), often rectangular root in basal view in lateroposterior teeth ( Figs. 9 E View Fig 4 View Fig , 11G View Fig 3 View Fig ) with a small but well demarcat- ed protuberance ( Figs. 9D View Fig 3 View Fig , E 4 View Fig , 11 View Fig G 3 View Fig , 12F 4 View Fig ), and moderately laterally expanded commissural teeth ( Fig. 11E View Fig ). Posteriorly situated upper lateroposterior teeth are greatly elongated in a mesiodistal direction in species of the C. appendiculata - and C. hattini groups ( Figs. 6E View Fig , 16E–H View Fig , 17L, M, 18G View Fig ).

Although the second upper anterior tooth of C. gertericorum sp. nov. ( Fig. 11A View Fig ) is inseparable from the A2s of C. borealis , the first lower anterior tooth at hand of the former is more slender ( Fig. 11F View Fig ) than is the corresponding tooth of C. borealis ( Fig. 10A View Fig ). The latter is admittedly a larger tooth (13% wider root), but the difference in size may not be enough to explain the marked difference in slenderness as part of the ontogenetic change in C. borealis -group species. The upper lateroposterior teeth of C. gertericorum sp. nov. differ from those of C. borealis by e.g., their more labially curved cusp in profile view ( Figs. 9D View Fig 2, E 2 View Fig , 11B View Fig 2 View Fig , D 4 View Fig , E 2 View Fig ) and differently shaped cusplets. In C. borealis the inner edge is typically convex whereas the outer edge is concave ( Fig. 9D View Fig 4 View Fig , E 1 View Fig ; Priem 1897: pl. 1: 4, 9; Lauginiger and Hartstein 1983: pl. 2: 14). In contrast, the average C. gertericorum sp. nov. tooth shows little difference in curvature between the inner and outer edges of the cusplets ( Fig. 11B, C View Fig ). In lateroposterior teeth of the same size (presumably adult C. gertericorum sp. nov. and juvenile C. borealis ) the cusp is considerably stereopair), profile (C 2), basal (C 3), and lingual (C 4) views. D. LO 11351t, left lateroposterior tooth from a juvenile individual; labial (D 1), profile (D 2), basal (D 3), and lingual (D 4) views. E. LO 11136t, left lateroposterior tooth; labial (E

1

, stereopair), profile (E

2

), lingual (E

3

), and basal (E

4

) views.

1

2

3

broader in C. gertericorum sp. nov. ( Fig. 11C View Fig 2 View Fig ) than it is in C. borealis ( Fig. 9D View Fig 1 View Fig ). The widening of the cusp is thus related to the ontogenetic stage in these two species rather than to absolute tooth size at species group level.

First and second upper anterior teeth of C. ewelli sp. nov. differ from those of C. borealis by their smaller, less divergent cusplets (the relative size of the cusplets does, however, overlap between the two species) and awl-shaped cusp ( Fig. 12B 1 View Fig ). In C. borealis , the cusp is labiolingually compressed in first and second upper anterior teeth to a much larger degree than it is in C. ewelli sp. nov. The awl-shaped cusp in first and second upper anterior teeth does not appear to simply be a juvenile feature in C. ewelli sp. nov. as this cusp shape is most pronounced in the largest anterior tooth at hand ( Fig. 12B). See the comparison section for C. sarcoportheta sp. nov. regarding dental differences between this species and C. borealis .

Priem (1897) described “ Lamna ” borealis on the basis of a large, upper lateroposterior tooth from the “chalk” yielding Belemnitella mucronata at Köping (= Stora Köpinge), Skåne, southern Sweden and on another, even larger upper lateroposterior tooth from the Faxe quarry (NP3 Zone, Danian), Demark, illustrated as Otodus appendiculatus by Davis (1890: pl. 41: 4). The tooth from Köpinge is here designated as lectotype. The designation is warranted because we have seen no evidence indicating that any species of Cretalamna of Campanian age ranges into the Danian stage. Unpublished otodontid material from the Danian (NP3 Zone) of the Limhamn quarry, Scania, southern Sweden, includes a large-toothed Cretalamna species (same taxon as the Faxe tooth above) probably closely related to C. borealis but nonetheless readily separable from the latter (e.g., lateral cusplets are much larger in anterior teeth of the Danian species and the median indentation of the basal edge of the root is considerably wider and deeper in lateroposterior teeth with a well-preserved root of this taxon). The selection of the Campanian tooth as lectotype rather than the Danian specimen from the Faxe quarry is based on the fact that the description by Priem (1897) is based primarily on the Campanian specimen.

The “chalk” in the Köpinge area is in fact a highly calcareous sandstone (“Köpinge sandstone”) and ranges in age on the basis of abundant belemnites and ammonites) from the latest early Campanian to the middle late Campanian Christensen 1986: 9).

The basal third of the labial face of the cusp in the lectotype is heavily wrinkled. This feature is present in two of the registered specimens from the informal Belemnellocamax mammillatus zone of the Kristianstad Basin; one upper lateroposterior tooth from Åsen (LO 11139t) and one lower lateroposterior tooth from Ugnsmunnarna (WAM 13.5.21). These teeth are not illustrated herein because of their poor state of preservation (severely abraded root). The mesial, well-preserved lateral margin of the root in the lectotype is vertical and the cusp is tall (for a lateroposterior position) and strongly distally curved. The inner edge of the cusplets is convex whereas the outer edge is straight or slightly concave. The tooth is inseparable at species level from upper lateroposterior teeth of a similar jaw position (middle part of the inferred upper lateroposterior hollow) referrable to a second species (besides C. sarcoportheta sp. nov.) of Cretalamna in the early Campanian of southern Sweden. The Kristianstad Basin specimens share two or more of the following characters that can be observed in the lectotype: (i) vertical lateral margin of one or both lobes of the root ( Fig. 9D View Fig 1, E 1 View Fig ); (ii) convex inner edge and straight or concave outer edge on one or both lateral cusplets ( Fig. 9D View Fig 1, E 1 View Fig ); (iii) tall, distally curved rather than distally inclined cusp ( Fig. 9D View Fig 1 View Fig ); (iv) coarsely wrinkled basal third of the labial face of the cusp (see above).

Lateroposterior teeth of C. borealis type occur together with tall anterior teeth, of a type referred to as C. appendiculata var. pachyrhiza by Herman (1977), in the informal B. mammillatus zone of the Kristianstad Basin ( Fig. 9B, C View Fig ). The co-occurrence of upper lateroposterior teeth of C.borealis type with anterior teeth of C. appendiculata var. pachyrhiza type indicates that the nominal C. appendiculata var. pachyrhiza is a junior synonym of C. borealis . Herman and Van Waes 2012) “elevated” the variety pachyrhiza (which, as such, is not regulated by the Code as it was published as a “variété” after 1960; ICZN 15.2) to species level although they used slightly different spelling ( Cretalamna pachyrhyza ) and inadvertently referred to Herman’s (1977) illustrations of C.

lata (Agassiz, 1843) rather than to his C. appendiculata var. pachyrhiza . As the nominal C. pachyrhyza lacks a defined holotype or syntypes it will not be considered further here.

Cretalamna borealis has consistently been regarded as a valid species over the last 30 years by Russian students. Glikman (1980) correctly grouped large, upper lateroposteri- or teeth ( Glikman 1980: pl. 21: 2, 3) of C. borealis type from Campanian deposits in the Kyzylkum desert with a tall upper anterior tooth ( Glikman 1980: pl. 21: 4) of C. “ appendiculata var. pachyrhiza ” type from the same deposit. Averianov and Popov (1995) listed C. borealis from a phosphatic conglomerate near the village of Shyrokyi Karamysh, approximately 50 km west of Saratov, Russia. On the basis of a molluscan assemblage, they assigned a late early Campanian age to this unit. One of us (MS) collected C. borealis from this horizon in 1997. In a study of Campanian elasmobranchs from Delaware, USA, Lauginiger and Hartstein (1983) correctly distinguished teeth of C. borealis (described by them as C. appendiculata pachyrhiza ) from the basal Mount Laurel Sand (early late Campanian in the three-fold North American division of the stage) from teeth of C. appendiculata group type (described as C. appendiculata lata ) from the late middle Campanian Marshalltown Formation.

Shimada et al. (2010) described isolated, shed teeth of Cretalamna (referred to as C. appendiculata ) found in direct association with a plesiosaur skeleton (holotype of Futabasaurus suzukii ) in the early Santonian Tamayama Formation, central Japan. The illustrations of 82 shed teeth indicate the presence of more than one species of Cretalamna . One incomplete (apex of cusp appears to be missing) anterior tooth with blunt cusplets ( Shimada et al. 2010: fig. 2.41) is similar to the A1 of C. borealis ( Fig. 9A View Fig ). Teeth from the middle part of the inferred lateroposterior hollow, typical for species of the C. borealis group (strongly distally curved cusp, divergent cusplets and relatively deeply excavated mesial concavity of the basal edge of the root), are represented by at least three specimens illustrated by Shimada et al. (2010: figs. 2.35, 47, 48; compare the latter tooth with the lectotype of C. borealis ). Two large and broad-bladed lateroposterior teeth ( Shimada et al. 2010: figs. 2.43, 2.69) correspond well with teeth from a similar position in C. hattini sp. nov. (Fig. 15).

Geographic and stratigraphic range.—Santonian of Japan (Honshu, Fukushima Prefecture); Campanian of Sweden (Scania Province), Belgium (Hainaut Province), France (Picardie and Poitou-Charentes Provinces), Russia (Saratov Oblast), Uzbekistan (Kyzylkum Desert), and USA (Delaware).

Kingdom

Animalia

Phylum

Chordata

Class

Elasmobranchii

Order

Lamniformes

Family

Otodontidae

Genus

Cretalamna

Loc

Cretalamna borealis ( Priem, 1897 )

Siversson, Mikael, Lindgren, Johan, Newbrey, Michael G., Cederström, Peter & Cook, Todd D. 2015
2015
Loc

Cretolamna appendiculata (Agassiz, 1843)

Siverson, M. 1992: 528
1992
Loc

Cretolamna appendiculata pachyrhiza

Lauginiger, E. M. & Hartstein, E. F. 1983: 31
1983
Loc

Lamna appendiculata (Agassiz, 1843)

Priem, F. 1897: 40
1897
Loc

Lamna borealis

Priem, F. 1897: 41
1897
Darwin Core Archive (for parent article) View in SIBiLS Plain XML RDF