S. M. Manton's (1973) polyphyletic Arthropod hypothesis with Uniramia as one of three Phyla.[1]
Uniramia (uni – one, ramus – branch, i.e. single-branches) is a group within the arthropods. In the past this group included the Onychophora, which are now considered a separate category. The group is currently used in a narrower sense.[2]
Onychophora like this Peripatoides sp. are no longer counted as unirames.
Uniramia is one of three subphyla in the Arthropoda classification suggested by Sidnie Manton. This classification divided arthropods into a three-phyla polyphyletic group, with phylum Uniramia including the Hexapoda (insects), Myriapoda (centipedes and millipedes) and the Onychophora (velvetworms). The discovery of fossillobopods, determined to be intermediate between onychophorans and arthropods led to the splintering of the Lobopoda and Onychophora into separate groups. This redefined the Uniramia as strictly "true" arthropods with exoskeletons and jointed appendages. Uniramians have strictly uniramous appendages.[2]
Systematics can result in rival taxonomies, and this seems to have happened to Uniramia. The name Uniramia was temporarily rejected as a polyphyletic group, but when used now refers to the subphylum consisting of the insects + myriapods. Subphylum Uniramia is characterized by uniramous (single-branching) appendages, one pair of antennae and two pairs of mouthparts (single pairs of mandibles and maxillae). Their body forms and ecologies are diverse. While most unirames are terrestrial, "some are aquatic for part or all of their life cycles.[2]" Atelocerata is described as replacing Uniramia in early twentieth-century texts (Heymons, 1901), where it was the preferred name for the category uniting the Hexapoda (insects) + Myriapoda; but depending on the source, the term Atelocerata may have replaced Mandibulata,[3] be an infraphylum beneath Mandibulata,[4] or may no longer be a valid category after closer, cladistics-based genetic study.[5]
The Crustacea were generally considered the closest relatives of the Uniramia, and sometimes these were united as Mandibulata. However, the competing hypothesis — that Crustacea and Hexapoda form a monophyletic group, the Pancrustacea, to which the Myriapoda are the closest relatives — has support from molecular and fossil evidence.
Notes
^Manton, S. M. 1973. Arthropod phylogeny-a modern synthesis. J. Zool. 171:111–130.
, Katherine McBride, Lindsey Moll, Whitney Zurat, Susquehanna University
at palaeos
March 05, 2023
uniramia, arthropoda, onychophorahexapodamyriapodacrustaceacheliceratas, manton, 1973, polyphyletic, arthropod, hypothesis, with, three, phyla, ramus, branch, single, branches, group, within, arthropods, past, this, group, included, onychophora, which, conside. Arthropoda Uniramia OnychophoraHexapodaMyriapodaCrustaceaChelicerataS M Manton s 1973 polyphyletic Arthropod hypothesis with Uniramia as one of three Phyla 1 Uniramia uni one ramus branch i e single branches is a group within the arthropods In the past this group included the Onychophora which are now considered a separate category The group is currently used in a narrower sense 2 As members of Myriapoda centipedes like this Scolopendra polymorpha are part of phylum Uniramia Onychophora like this Peripatoides sp are no longer counted as unirames Uniramia is one of three subphyla in the Arthropoda classification suggested by Sidnie Manton This classification divided arthropods into a three phyla polyphyletic group with phylum Uniramia including the Hexapoda insects Myriapoda centipedes and millipedes and the Onychophora velvetworms The discovery of fossil lobopods determined to be intermediate between onychophorans and arthropods led to the splintering of the Lobopoda and Onychophora into separate groups This redefined the Uniramia as strictly true arthropods with exoskeletons and jointed appendages Uniramians have strictly uniramous appendages 2 Systematics can result in rival taxonomies and this seems to have happened to Uniramia The name Uniramia was temporarily rejected as a polyphyletic group but when used now refers to the subphylum consisting of the insects myriapods Subphylum Uniramia is characterized by uniramous single branching appendages one pair of antennae and two pairs of mouthparts single pairs of mandibles and maxillae Their body forms and ecologies are diverse While most unirames are terrestrial some are aquatic for part or all of their life cycles 2 Atelocerata is described as replacing Uniramia in early twentieth century texts Heymons 1901 where it was the preferred name for the category uniting the Hexapoda insects Myriapoda but depending on the source the term Atelocerata may have replaced Mandibulata 3 be an infraphylum beneath Mandibulata 4 or may no longer be a valid category after closer cladistics based genetic study 5 Chelicerata ArachnidaMerostomataPycnogonidaTrilobitomorphaUniramia Myriapoda SymphylaChilopodaDiplopodaHexapoda EntognathaEctognathaCrustaceaUniramia as a Subphylum 6 The Crustacea were generally considered the closest relatives of the Uniramia and sometimes these were united as Mandibulata However the competing hypothesis that Crustacea and Hexapoda form a monophyletic group the Pancrustacea to which the Myriapoda are the closest relatives has support from molecular and fossil evidence Notes Edit Manton S M 1973 Arthropod phylogeny a modern synthesis J Zool 171 111 130 a b c Introduction to the Uniramia University of California Berkeley Retrieved October 1 2010 Phylum Arthropoda Archived from the original on 2009 02 24 Retrieved 2009 06 24 Atelocerata Infraphylum Archived from the original on June 25 2009 Retrieved June 24 2009 Demise of the Atelocerata Homeotic genes and the evolution of arthropods and chordates The case of the velvet worm Brusca R C amp G J Brusca 1990 Invertebrates Sinauer References EditPaleos Metazoa Arthropoda Uniramia Bio 105 106 demoExternal links EditA Cladistic Analysis of Arthropoda Examining the Evolution of Biramous Appendages and Mandibles Katherine McBride Lindsey Moll Whitney Zurat Susquehanna University Uniramia at palaeos Retrieved from https en wikipedia org w index php title Uniramia amp oldid 1132584182, wikipedia, wiki, book, books, library,
