Sturgeon biodiversity and conservation

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Figure 27. Proposed interrelationships of the genera of Acipenseridae: Huso is defined by two synapomorphies forming the subfamily
Husinae recognized as the sister group to the Acipenserinae. Acipenser is not recognized by any skeletal synapomorphies. Shovelnose
sturgeons of Scaphirhynchus and Pseudoscaphirhynchus compose Scaphirhynchini.
(Figure 27). The family Acipenseridae is supported
by 24 skeletal synapomorphies (Characters 1–24).
The genus Huso is defined by two synapomorphies
(Characters 25,26) and is the sister group to a redefined
subfamily Acipenserinae defined by 12 synapomorphies
(Characters 27–38) comprising all
other genera. Scaphirhynchus and Pseudoscaphirhynchus
compose a monophyletic tribe Scaphirhynchini
based on 16 synapomorphies (Characters
39–54). Pseudoscaphirhynchus is defined by five
synapomorphies (Characters 55–59) and Scaphirhynchus
is defined by 10 synapomorphies (Characters
60–69). Each node is supported by characters
from different skeletal complexes suggestive of
multiple evolutionary events occurring at one node
rather than a one event affecting multiple characters.
A remaining phylogenetic problem is the lack of
identified synapomorphies defining the genus Acipenser,
leaving this largest genus (17 species) as po-