Pseudopulicidae is an extinct family of

stem-group In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. ...

flea Flea, the common name for the order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by ingesting the blood of their hosts. Adult fleas grow to about long, a ...

s from the

Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

of China. They represent the oldest known group of stem-fleas. Like other stem-group "giant fleas", they are much larger and lack the specialised morphology of modern fleas.

Description

Pseudpulicids are much larger than modern fleas, varing from 8 mm to over 2cm in body length. The females of the species are always larger than the males. The body is flattened, with a non-reduced thorax, and covered in posterior facing hairs (setae). The antennae are relatively compact, with at least 16

antennomeres Antennae ( antenna), sometimes referred to as "feelers", are paired appendages used for Sensory system, sensing in arthropods. Antennae are connected to the first one or two Segmentation (biology), segments of the arthropod head. They vary widel ...

, and 14-17 flagellomeres. The mouthparts are siphonate, with a piercing-suctorial function, and are serrated and longer in females. The distal (outer) part of the

tibia The tibia (; ), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outside of the tibia); it connects ...

are covered in comb-like ctenidia, the tarsi are elongate, at least as long as

femora The femur (; ), or thigh bone, is the proximal bone of the hindlimb in tetrapod vertebrates. The head of the femur articulates with the acetabulum in the pelvic bone forming the hip joint, while the distal part of the femur articulates with t ...

and tibia combined. The male abdominal sternites are sclerotized, and the penis of the males is large and exposed.

Ecology

The hosts of pseudpulicids and other extinct stem-fleas are unknown, proposed hosts have included primitive

mammals Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

dinosaurs Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

, and

pterosaurs Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to ...

Taxonomy

* '' Pseudopulex'' Gao, Shih, and Ren, 2012 ** ''P. jurassicus'' Gao, Shih, and Ren, 2012

Daohugou The Haifanggou Formation (), also known as the Jiulongshan Formation (), is a fossil-bearing rock deposit located near Daohugou () village of Ningcheng County, in Inner Mongolia, northeastern China. The formation consists of coarse conglomerates ...

, China, Middle Jurassic (

Bathonian In the geologic timescale the Bathonian is an age and stage of the Middle Jurassic. It lasted from approximately 168.3 Ma to around 166.1 Ma (million years ago). The Bathonian Age succeeds the Bajocian Age and precedes the Callovian Age. Strat ...

) ** ''P. magnus'' Gao, Shih, and Ren, 2012

Yixian Formation The Yixian Formation (; formerly transcribed as Yihsien Formation) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans the late Barremian and early Aptian stages of the Early Cretaceous. It is known for its ex ...

, China, Early Cretaceous (

Aptian The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), a ...

) ** ''P. tanlan'' Gao, Shih, Rasnitsyn, and Ren, 2014 Yixian Formation, China, Early Cretaceous (Aptian) ** ''P. wangi'' Huang, Engel, Cai, and Nel, 2013 Daohugou, China, Middle Jurassic (Bathonian) * '' Tyrannopsylla beipiaoensis'' Huang, Engel, Cai, and Nel, 2013 Yixian Formation, China, Early Cretaceous (Aptian) * '' Hadropsylla sinica'' Huang, Engel, Cai, and Nel, 2013 Daohugou, China, Middle Jurassic (Bathonian)

References

{{Taxonbar, from=Q19769223 Fleas Prehistoric insect families