Cannabaceae

Pakucaris
Temporal range: Miaolingian
Life restoration
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Order: Hymenocarina
Genus: Pakucaris
Izquierdo-López & Caron, 2021
Species:
P. apatis
Binomial name
Pakucaris apatis
Izquierdo-López & Caron, 2021

Pakucaris is an extinct genus of bivalved arthropod known from a single species, Pakucaris apatis, found in the Marble Canyon locality of the Burgess Shale in British Columbia, Canada. It is thought to be a member of Hymenocarina. Unlike other members of that group, the posterior segments are covered with a separate pygidium shield, covergent on other arthropods like artiopods. Specimens range in length from 11.65 to 26.6 millimetres (0.459 to 1.047 in). The main bivalved carapace covers around 80% of the body, with the pygidium covering the remaining 20%. The head has a forward and downward facing pair of moderately sized eyes on short stalks, along with three pairs of cephalic appendages. The thorax has either 30-35 or 70-80 segments, depending on the specimen, while the pygidium has either 11-13 or 20 segments. The segments of the thorax and pygidium have pairs of thin filamentous limbs divided into 20/21 podomeres, with paddle-like exopods. It was probably nektobenthic (actively swimming close to the seafloor), and its ecology was likely that of a selective suspension feeder, using its limbs to scrape and/or suspend food particles from the sea floor, before using its limbs to capture and transfer them to the mouth.[1]

References

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  1. ^ Izquierdo‐López, Alejandro; Caron, Jean‐Bernard (November 2021). Zhang, Xi‐Guang (ed.). "A Burgess Shale mandibulate arthropod with a pygidium: a case of convergent evolution". Papers in Palaeontology. 7 (4): 1877–1894. doi:10.1002/spp2.1366. ISSN 2056-2799. S2CID 236284813.

One thought on “Cannabaceae

  1. Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
    View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction

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