Acipenser

Prior to 2025, Acipenser contained almost all species in the Acipenseridae outside of Huso and the "shovelnose" sturgeons (Scaphirhynchus and Pseudoscaphirhynchus). However, such a placement is now known to be paraphyletic with respect to the other genera, and these species have since been split into Huso and Sinosturio. Acipenser in the strict sense (sensu stricto) has been redefined with only 3 species.^[3]

This is an ancient genus, with phylogenetic evidence suggesting that it is the most basal sturgeon genus, having diverged from other sturgeons during the Early Cretaceous period. Several fossil species known as far back as the Late Cretaceous, with the fossils of two species (A. praeparatorum and A. amnisinferos) known from mass mortality assemblages thought to immediately follow the Chicxulub impact, the beginning of the Cretaceous-Paleogene extinction event.^[4] However, the classification of these fossil species is uncertain under the new taxonomy; for example, "Acipenser" praeparatorum may actually represent a more derived sturgeon related to the Huso-Pseudoscaphirhynchus lineage.^[3]

The following three species are placed in this genus:^[2]

• Acipenser desotoi Vladykov, 1955 (Gulf sturgeon)
• Acipenser oxyrinchus Mitchill, 1815 (Atlantic sturgeon)
• Acipenser sturio Linnaeus, 1758 (type species) (European sea sturgeon)

The following species are known from fossil remains, under a sensu lato interpretation of the genus. Almost all aside from A. anisinferos and A. praeparatorum^[5] are thought to be nomina dubia.^[6]

• †Acipenser albertensis Lambe, 1902 (Late Cretaceous of Alberta, Canada)
• †Acipenser amnisinferosHilton & Grande, 2023 (Late Cretaceous of North Dakota, USA)^[7]
• †Acipenser chilini Nessov, 1983 (Early Paleocene of Kazakhstan)
• ?†Acipenser cretaceous Daimeries, 1892 (Late Cretaceous of Belgium; potentially a teleost)
• †Acipenser eruciferus Cope, 1876 (Late Cretaceous of Montana, USA)
• †Acipenser gigantissimus Nessov, 1997 (Late Cretaceous of Saratov, Russia)^[8]
• †Acipenser lemoinei (Priem, 1901) (Early Eocene of France)
• ?†Acipenser molassicus Probst, 1882 (Miocene of Germany; potentially a chondrichthyan)
• †Acipenser ornatus Leidy, 1873 (Miocene of Virginia, USA)
• †Acipenser parisiensis Priem, 1908 (Early Oligocene of France)
• †Acipenser praeparatorum Hilton & Grande, 2023 (Late Cretaceous of North Dakota, USA)^[7]
• †Acipenser toliapicus Agassiz 1844 ex Woodward 1889 (Early Eocene of England)
• ?†Acipenser tuberculosus Probst 1882 (Miocene of Germany; potentially a chondrichthyan)
• †Acipenser zhylgensis Nessov, 1983 (Early Paleocene of Kazakhstan)