Squatiniformes is an order of sharks belonging to
Squalomorphi
Squalomorphi is a superorder of sharks, generally characterized by lacking traits such as an anal fin, nictitating membrane, or suborbital shelves in the cranium. Squalomorphs are also called squalea, or squaleans. There are about 163 living spec ...
. It contains only a single living genus ''
Squatina'', commonly known as angelsharks. The oldest genus of the order, ''
Pseudorhina'' is known from the
Late Jurassic
The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen ...
of Europe.
Three other genera, ''
Cretasquatina'', ''
Cretascyllium'' and ''
Parasquatina'' are known from
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
fossils from North America and Europe,
though the placement of ''Parasquatina'' in the order has been questioned.
All living and extinct members of the order share a similar body morphology
with a highly flattened body with enlarged pectoral and pelvic fins suggestive of a
bottom-dwelling ambush predator
Ambush predators or sit-and-wait predators are carnivorous animals that capture their prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey u ...
ecology.
Teeth have been assigned to the modern genus from the Late Jurassic onwards, but the actual genus assignment of many of these species is unclear.
The earliest records that can be assigned with confidence to the modern genus are known from the Early Cretaceous (
Aptian
The Aptian is an age (geology), age in the geologic timescale or a stage (stratigraphy), stage in the stratigraphic column. It is a subdivision of the Early Cretaceous, Early or Lower Cretaceous epoch (geology), Epoch or series (stratigraphy), S ...
) of England.
References
{{Taxonbar, from=Q15207720
Cartilaginous fish orders
Taxa named by Fernando de Buen y Lozano