Late Cretaceous (Campanian) actinopterygian fishes from the Kristianstad Basin of southern Sweden

Abstract

Although a diverse range of aquatic vertebrates are documented from the Upper Cretaceous (mid-Campanian) marine strata of the Kristianstad Basin in southern Sweden, only chondrichthyans and marine amniotes have been described in detail to date. In contrast, coeval actinopterygians are virtually unreported, yet their remains are extremely abundant at most sampled localities. A comprehensive assessment of these fossils has identified the first Late Cretaceous actinopterygian fauna from the Fennoscandian Shield, incorporating indeterminate lepisosteids, the durophagous pycnodontid Anomoeodus subclavatus, the predatory pachycormid Protosphyraena sp., a large ichthyodectid, pachyrhizodontids resembling Pachyrhizodus, the enchodontid Enchodus cf. gladiolus and indeterminate small teleosts. These taxa are diagnosed mainly from isolated teeth and scales, implying substantial taphonomic loss prior to burial. Moreover, the prolific recovery of actinopterygian skeletal remnants in recent excavations suggests that historical collecting biases, rather than ecological paucity, have contributed to their under-representation in the Swedish Cretaceous record. Palaeobiogeographically, the Kristianstad Basin actinopterygians show compositional resemblance to assemblages from the Northern European Platform and the Western Interior Seaway of North America, advocating distributional communication across the Boreal proto-Atlantic Ocean.

Two-step extinction of Late Cretaceous marine vertebrates in northern Gulf of Mexico prolonged biodiversity loss prior to the Chicxulub impact

“…Many studies on marine vertebrate extinctions have emphasized the end-Maastrichtian event (e.g., marine reptiles 4,6,8 , mosasaurs 7 , plesiosaurs 21 , sharks 11 , bony fish 5 ) while a few studies have also pointed out the possibility of Campanian extinctions (e.g., actinopterygian and mosasaur fauna in Sweden 22,23 ). Our study suggests that species-level data from a selected geographic region have some advantages to reveal the Middle Campanian biodiversity loss.…”

The impact of the Maastrichtian cooling on the marine nutrient regime—Evidence from midlatitudinal calcareous nannofossils

“…The belemnite family Belemnitellidae, which is quite common in the late Cretaceous sediments of the North Sea Basin [e.g., Christensen , ], is also known from the northern part of the Tethys (e.g., Belemnella and Gonioteuthis ) and from the Western Interior Basin (e.g., Praeactinocamax and Belemnitella ). Fish faunas (actinopterygian fishes and chondrichthyans) document similarities on the species level between the North Sea Basin, the Western Interior Basin, and parts of the Tethys [e.g., Cumbaa et al ., ; Bazzi et al ., ]. Similar cosmopolitan distribution patterns are also seen in mosasaurs [e.g., Lindgren and Siverson , ] and aquatic bird faunas [e.g., Rees and Lindgren , ].…”

The first Peruvian record of Enchodus (Actinopterygii, Aulopiformes, Enchodontidae) in the Upper Cretaceous Vivian Formation

“…However, the material is too fragmentary and should be compared with teeth of African species (see Arambourg, 1952). Teeth resembling E. gladiolus were also reported from the Campanian of Sweden (Bazzi et al, 2015). However, those teeth do not have the postapical barb and the ridges are extremely faint (see Bazzi et al, 2015, fig 5C).…”