Pristis, Linck, 1790

Ebersole, Jun A., Cicimurri, David J. & Stringer, Gary L., 2019, Taxonomy and biostratigraphy of the elasmobranchs and bony fishes (Chondrichthyes and Osteichthyes) of the lower-to-middle Eocene (Ypresian to Bartonian) Claiborne Group in Alabama, USA, inclu, European Journal of Taxonomy 585, pp. 1-274: 110-111

publication ID

https://doi.org/10.5852/ejt.2019.585

publication LSID

lsid:zoobank.org:pub:181B6FBA-ED75-4BB4-84C4-FB512B794749

DOI

http://doi.org/10.5281/zenodo.3664627

persistent identifier

http://treatment.plazi.org/id/18174D41-FFE8-FFC1-FD19-9C744E3A091D

treatment provided by

Plazi

scientific name

Pristis
status

 

Pristis  sp.

Fig. 39View Fig S–GG

Pristis lathami – Holman & Case 1988: 328  . — Cappetta & Case 2016: 63–64, pl. 11, figs 1–2.

Material examined

UNITED STATES OF AMERICA – Alabama • 247 isolated teeth; Claiborne Group ; ALMNH PV1989.4.108 (36 specimens), ALMNH PV1985.87.11, ALMNH PV1985.87.12, ALMNH PV1985.87.13, ALMNH PV1985.87.14, ALMNH PV1985.87.15, ALMNH PV1985.87.16, ALMNH PV1985.87.17, ALMNH PV1985.87.18, ALMNH PV1985.87.19, ALMNH PV1985.87.20, ALMNH PV1985.87.21, ALMNH PV1985.87.22, ALMNH PV1985.87.23, ALMNH PV1985.87.24, ALMNH PV1985.87.25, ALMNH PV1985.87.26, ALMNH PV1985.87.27, ALMNH PV1985.87.28, ALMNH PV1985.87.29, ALMNH PV1985.87.30, ALMNH PV1985.87.31, ALMNH PV1985.87.32, ALMNH PV1985.87.53, ALMNH PV1985.87.54, ALMNH PV1985.87.6, ALMNH PV1989.4.10.1 (3 specimens), ALMNH PV 1989.4.14 (2 specimens), ALMNH PV1989.4.151.2 (4 specimens), ALMNH PV1989.4.17.2 (7 specimens), ALMNH PV1989.4.46, ALMNH PV1989.4.57, ALMNH PV1989.4.75.1, ALMNH PV1989.4.78 (2 specimens), ALMNH PV1989.4.92 (2 specimens), ALMNH PV1990.7View Materials, ALMNH PV1992.28.12, ALMNH PV1992.28.20 (2 specimens), ALMNH PV1992.28.8 (2 specimens), ALMNH PV1992.28.8 (2 specimens), ALMNH PV1992.56.4 (22 specimens), ALMNH PV1993.2.488, ALMNH PV2000.1.43.13 (2 specimens), MMNS VP-5640 (23 specimens), MMNS VP-8221 (6 specimens), MSC 2150.2, MSC 2150.4, MSC 2175.30, MSC 2392.1 3, MSC 2392.9, MSC 2395.5, MSC 33249, MSC 33364, MSC 33378, MSC 33390, MSC 33528, MSC 33548, MSC 33570, MSC 33646, MSC 33650, MSC 33666, MSC 33691, MSC 33888, MSC 33890, MSC 33905, MSC 34406.1 5, MSC 34621View Materials, MSC 35737.1 3, MSC 35790.1 5, MSC 37134.1 6, MSC 37169View Materials, MSC 37182.1 3, MSC 37277View Materials, MSC 37334.1 8, MSC 37437.1 25, MSC 37439, MSC 37458, MSC 37525, MSC 37617, MSC 38399, MSC 38628, MSC 38788, NJSM 24030View Materials (2 specimens), SC 2012.47.169 (2 specimens), SC 2012.47.93 (9 specimens), WSU 5026View Materials  .

Description

Rostral spines attain large sizes, some reaching 10cm in length. Rostral spines long, slender.Spines generally straight, may curve ventrally; dorsal and ventral surfaces slightly convex anteroposteriorly. Anterior spine edge rounded; posterior edge generally concave, with sharp dorsal and ventral edges. Apical portion of anterior edge sharp, slightly convex, forms sharp point with posterior edge. Anterior and posterior edges nearly parallel, slightly wider basally. Longitudinal striations sometimes visible on basal portion of the spine. Growth bands perpendicular to spine length visible on some spines. Medial margins of rostral spines flat to slightly concave. Some spines with flat posterior margin. Rostral spines lack enameloid.

Remarks

Cappetta (2012) and Cappetta & Case (2016) recognized the following species of Eocene Pristis  : P. amblodon Cope, 1869  ; P. brayi Casier, 1949  ; P. lathami Galeotti, 1837  ; P. olbrechtsi Dartevelle & Casier, 1959  ; P. pickeringi Case, 1981  ; and P. prosulcatus Stromer, 1905a  . Cappetta & Case (2016) noted two morphologies of Pristis  rostral spines from the ACov-11 locality that they assigned to “ Pristis  sp. 1” and “ Pristis  sp. 2.” The two morphologies were differentiated based on supposedly unique ornamentation and by being “thicker”, and the authors suggested that a new species may be represented. Pristis lathami Galeotti, 1837  is the name most frequently assigned to isolated Eocene Pristis  rostral spines (see Cappetta 2012; Cappetta & Case 2016), but we refrain from speciating any of the isolated Claiborne spines because of the variation observable on fossil and extant Pristis  rostral spines, and our lack of knowledge of the post-rostrum skeletal morphology of the extinct species. Variation in spine shape may be the result of several factors, including ontogeny, in vivo wear and, potentially, heterodonty. Pristis  rostral spines are not replaced but instead increase in size over the lifespan of the animal ( Slaughter & Springer 1968). Spines of older animals are large, dorsoventrally thicker, have deeper posterior grooves, and are often more worn than their smaller/younger counterparts. There is also potential for heterodonty in our sample based on preserved specimens at MSC and SC, where the spines in the rostra of extant Pristis  tend to be shorter at the posterior end of the rostrum than those located more anteriorly. Due to this range of variation, it is our opinion that a conservative approach be taken when identifying isolated fossil Pristis  rostral spines because one or more of the described species are likely nominal. We also believe that the absence of a posterior groove is not related to ontogeny, as the posterior margin of both small and large spines may be flat or slightly concave.

It is interesting to note that certain spines in our sample exhibit faint striations on the dorsal and ventral surfaces, oblique to the anterior/posterior edges, near the spine tip. These are identical to what was described by Cicimurri (2007) on middle Eocene spines from South Carolina and has been observed on spines of extant species ( Allen 1999). The sharp anterior edge, pointed tip, and faint dorsal/ventral striations are believed to be the result of the sawfish using the spined rostrum to probe the sea floor in search of prey animals.

Stratigraphic and geographic range in Alabama

The specimens in our sample were collected from the lower Tallahatta Formation at site ADl-1, the contact of the Tallahatta and Lisbon formations at sites ACh-14 and ACov-11, the basal Lisbon Formation at site ACov-11, the basal Gosport Sand at sites ACl-4 and AMo-4, and the Gosport Sand at site ACh-21. Upper Ypresian to middle Bartonian, zones NP14 to NP17.

ALMNH

Alabama Museum of Natural History

Kingdom

Animalia

Phylum

Chordata

Class

Elasmobranchii

Order

Pristiformes

Family

Pristidae

Loc

Pristis

Ebersole, Jun A., Cicimurri, David J. & Stringer, Gary L. 2019
2019
Loc

Pristis lathami –

Holman J. A. & Case G. R. 1988: 328