Cryptoclididae is a

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

of medium-sized plesiosaurs that existed from the Middle

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

to the Early

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

. They had long necks, broad and short skulls and densely packed teeth. They fed on small soft-bodied preys such as small fish and

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...

s. The earliest members of the family appeared during the early

Bajocian In the geologic timescale The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relatin ...

, and they represented the dominant group of long-necked plesiosaurs during the latter half of the Jurassic.

Classification

In 2010, two supposed late Cretaceous members of the group were reclassified as other kinds of plesiosauroids. ''

Kaiwhekea ''Kaiwhekea'' () is an extinct genus of plesiosaur from the Late Cretaceous (Maastrichtian age) of what is now New Zealand. History of discovery The type species, ''Kaiwhekea katiki'', was first described by Arthur Cruickshank and Ewan Fordy ...

'' was reclassified to

Leptocleididae Leptocleididae is a family of small-sized plesiosaurs that lived during the Early Cretaceous period (early Berriasian to early Albian stage). They had small bodies with small heads and short necks. '' Leptocleidus'' and '' Umoonasaurus'' had rou ...

, and ''

Aristonectes ''Aristonectes'' (meaning 'best swimmer') is an extinct genus of plesiosaur from the Late Cretaceous Paso del Sapo Formation of what is now Argentina, the Quiriquina Formation of Chile and the Lopez de Bertodano Formation of Antarctica. The t ...

'' was transferred to

Elasmosauridae Elasmosauridae is an extinct family of plesiosaurs, often called elasmosaurs. They had the longest necks of the plesiosaurs and existed from the Hauterivian to the Maastrichtian stages of the Cretaceous, and represented one of the two groups ...

Cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to ...

based on Ketchum and Benson (2010):

References

External links

palaeos.com
Jurassic plesiosaurs Cretaceous plesiosaurs Callovian first appearances Late Cretaceous extinctions Prehistoric reptile families {{Jurassic-reptile-stub