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| Pseudocorax heteroserratus Egli, Goode, Rempert & Rego, 2025 |
Abstract
A new species of Pseudocorax (Lamniformes, Pseudocoracidae), Pseudocorax heteroserratus n. sp., is described from the upper Maastrichtian phosphates of Morocco. This novel taxon is recognized by a large sample of isolated teeth collected from the upper Couche III layer at the Sidi Chennane quarry in the Oulad Abdoun Basin, Khouribga Province, Morocco. P. heteroserratus is differentiated from other Pseudocorax species by bearing a mesiodistally elongated tooth base, broad crown, and highly variable serrations. The variability in number and extent of serrations along the carinae ranges from completely absent to fully serrated and finely to coarsely serrated, raising speculation on broader Pseudocorax phylogenetics and as to whether the genesis of serrations within Pseudocorax occurred in a singular progressive event or rather from two distinct events. The morphological variability within the new species highlights the importance of large sample sizes in selachian odontological studies using isolated teeth.
Systematic paleontology
Class Chondrichthyes Huxley, Reference Huxley, 1880
Subclass Elasmobranchii Bonaparte, Reference Bonaparte, 1838
Cohort Euselachii Hay, Reference Hay, 1902
Subcohort Neoselachii Compagno, Reference Compagno, 1977
Order Lamniformes Berg, Reference Berg, 1958
Family Pseudocoracidae Cappetta, Reference Cappetta, 2012
Genus Pseudocorax Priem, Reference Priem, 1897
Type species: Pseudocorax affinis (Münster in Agassiz, Reference Agassiz1843), from the upper Maastrichtian, Netherlands.
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| Upper anterior Pseudocorax heteroserratus n. sp. (1–5) MMNS VP-12820 (holotype), upper left anterior tooth in (1) lingual, (2) basal, (3) apical, (4) profile, and (5) labial views. (6–10) MMNS VP-12827.01, upper left anterior tooth in (6) lingual, (7) basal, (8) apical, (9) profile, and (10) labial views. Scale bars = 5 mm. |
Pseudocorax heteroserratus new species
Diagnosis: Crown and tooth base mesiodistally expanded, especially along upper and lower jaw anterior teeth. Mesial shoulder generally more prominent along basal crown, extending further apically. Variable serrations, from absent to full and coarse to fine, regardless of jaw position or potential ontogenetic stage. Deep basal margin on tooth base with variable tooth base lobe morphology.
Occurrence: Upper Couche III layer of the Oulad Abdoun Basin, Sidi Chennane quarry, near Oued Zem, Khouribga Province, Morocco.
Etymology: “Hetero-”, Latin for “different”, and “serratus” for “serrations,” highlighting the variability in the presence and size of serrations along the crown.
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| Upper lateroposterior Pseudocorax heteroserratus n. sp. teeth. (1–5) MMNS VP-12823 (paratype), upper left lateroposterior tooth in (1) lingual, (2) basal, (3) apical, (4) profile, and (5) labial views. (6–10) MMNS VP-12827.05, (?) upper right lateroposterior tooth in (6) lingual, (7) basal, (8) apical, (9) profile, and (10) labial views. (11–15) MMNS VP- 12827,06, (?) upper left lateroposterior tooth in (11) lingual, (12) basal, (13) apical, (14) profile, and (15) labial views. (16–20) MMNS VP-12827.07, upper left lateroposterior tooth in (16) lingual, (17) basal, (18) apical, (19) profile, and (20) labial views. (21–25) MMNS VP-12827.08, upper right lateroposterior tooth in (21) lingual, (22) basal, (23) apical, (24) profile, and (25) labial views. (26–30) MMNS VP-12827.09, upper left lateroposterior tooth in (26) lingual, (27) basal, (28) apical, (29) profile, and (30) labial. Scale bars = 5 mm. |
Hunter Chase Egli, Benjamin Goode, Trevor Rempert and Christopher Rego. 2025. Pseudocorax (Chondrichthyes, Lamniformes, Pseudocoracidae) in the Upper Maastrichtian phosphates of Khouribga Province, Morocco. Journal of Paleontology. Journal of Paleontology. DOI: doi.org/10.1017/jpa.2025.10183 [21 November 2025]
Non-technical Summary: A new species of extinct shark, Pseudocorax heteroserratus n. sp., has been identified through isolated teeth from fossil-rich Cretaceous rock in Morocco. Unlike previously known Pseudocorax species, this new species is distinguishable through its broad crown, elongated tooth base, and unusually variable serrations. These serrations range from unserrated to coarsely serrated and provide new insights into Pseudocorax evolutionary history. It raises the question of whether serrations in this lineage evolved gradually in a continuous process or from multiple independent origins. The findings of this study emphasize how large sample sizes of shark teeth are critical in palaeoichthyology, especially when species are known only from their teeth.
