Yukoniidae S. Zhang, 1980 [nom. transl. et emend. Jell, in Whittington et al., 1997 ex Yukoniinae S. Zhang in W. Zhang, Lu et al., 1980] is a small family of trilobites, belonging to the Eodiscina. [1][2]
Yukoniidae are typically isopygous, belonging to the Superfamily Eodiscoidea. The narrow glabella is usually parallel sided, anteriorly rounded and separated from smooth anterior border by broad (sag.) preglabellar field which occupies about 25% of cephalic length excluding occipital spine. Posterior glabellar furrows are reduced to a pair of slits low on sides of glabella and directed backwards. Occipital ring bears a strong backwardly directed spine. Yukonia intermedia Palmer (1968) has three thoracic segments, the anterior of which has strong backwardly directed pleural spines. Pygidium of Yukoniidae has an axis of three to seven rings.[5]
Referencesedit
^S. M. GON III. "Order Agnostida". Retrieved December 3, 2010.
^ PALMER, A. R. 1968, Cambrian trilobites of east-central Alaska. Prof. Pap. U. S. Geol. Surv., 559-B pp. B1-B115, pls. 1-15.
^JELL, P.A. (1975). "Australian Middle Cambrian Eodiscoids with a review of the superfamily". Palaeontographica Abteilung A. 150: 1–97. cited in H.B. WHITTINGTON; et al., eds. (1997). Part O, Treatise on Invertebrate Paleontology. Revised, Volume 1 – Trilobita – Introduction, Order Agnostida, Order Redlichiida.
^WHITTINGTON, H.B.; et al. (1997). Introduction, Order Agnostida, Order Redlichiida. Treatise on Invertebrate Paleontology. Vol. Part O.Revised, Volume 1 – Trilobita. Boulder, Colorado/Lawrence, Kansas: Geological Society of America/University of Kansas Press. pp. 398–400. ISBN0-8137-3108-9.
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yukoniidae, zhang, 1980, transl, emend, jell, whittington, 1997, yukoniinae, zhang, zhang, 1980, small, family, trilobites, belonging, eodiscina, temporal, range, atdabanian, toyonian, preꞒ, nscientific, classificationkingdom, animaliaphylum, arthropodaclass, . Yukoniidae S Zhang 1980 nom transl et emend Jell in Whittington et al 1997 ex Yukoniinae S Zhang in W Zhang Lu et al 1980 is a small family of trilobites belonging to the Eodiscina 1 2 YukoniidaeTemporal range Atdabanian to Toyonian PreꞒ Ꞓ O S D C P T J K Pg NScientific classificationKingdom AnimaliaPhylum ArthropodaClass TrilobitaOrder AgnostidaSuborder EodiscinaSuperfamily EodiscoideaFamily YukoniidaeS Zhang 1980generaYukonia Palmer 1968 Alaskadiscus S Zhang in W Zhang Lu et al 1980 Egyngolia Korobov 1980 Atdabanian Ekwipagetia Fritz 1973 Atdabanian Lenadiscus Repina in Khomentovskii amp Repina 1965 Botomian Yukonides Fritz 1972 Atdabanian Contents 1 Type Genus and species 2 Taxonomy 3 Description 4 ReferencesType Genus and species editYukonia intermedia Palmer 1968 Plate 2 figures 14 17 19 22 23 27 28 text figure 4 3 Taxonomy editThe Yukoniidae probably descended from the Tsunydiscidae and gave rise to the Eodiscidae 4 Description editYukoniidae are typically isopygous belonging to the Superfamily Eodiscoidea The narrow glabella is usually parallel sided anteriorly rounded and separated from smooth anterior border by broad sag preglabellar field which occupies about 25 of cephalic length excluding occipital spine Posterior glabellar furrows are reduced to a pair of slits low on sides of glabella and directed backwards Occipital ring bears a strong backwardly directed spine Yukonia intermedia Palmer 1968 has three thoracic segments the anterior of which has strong backwardly directed pleural spines Pygidium of Yukoniidae has an axis of three to seven rings 5 References edit S M GON III Order Agnostida Retrieved December 3 2010 MIKKO HAARAMO March 11 2008 Yukoniidae Mikko s Phylogeny Archive Retrieved December 3 2010 PALMER A R 1968 Cambrian trilobites of east central Alaska Prof Pap U S Geol Surv 559 B pp B1 B115 pls 1 15 JELL P A 1975 Australian Middle Cambrian Eodiscoids with a review of the superfamily Palaeontographica Abteilung A 150 1 97 cited in H B WHITTINGTON et al eds 1997 Part O Treatise on Invertebrate Paleontology Revised Volume 1 Trilobita Introduction Order Agnostida Order Redlichiida WHITTINGTON H B et al 1997 Introduction Order Agnostida Order Redlichiida Treatise on Invertebrate Paleontology Vol Part O Revised Volume 1 Trilobita Boulder Colorado Lawrence Kansas Geological Society of America University of Kansas Press pp 398 400 ISBN 0 8137 3108 9 nbsp This Agnostida related article is a stub You can help Wikipedia by expanding it vte Retrieved from https en wikipedia org w index php title Yukoniidae amp oldid 1064073509, wikipedia, wiki, book, books, library,
