Palaeospondylidae、おさかなマガジン 分類トップ


Family Palaeospondylidae WOODWARD パラエオスポンディルス科
Gunn's Ancient Vertebrae (Palaeospondylus gunnii)
Palaeospondylids (パラエオスポンディルス科魚種)

Genus Palaeospondylus TRAQUAIR 1890 パラエオスポンディルス属 (絶滅)
    ※← [Cycliae DEAN 1899]。
    ※← [Palaeospondyliformes BERG 1940]。≠Palaeospondylidae STÜRTZ 1899 [Lapworthuridae, Ophiuroidea, Echinodermata]。
    ※← [Palaeospondyloidea BLACKWELDER 1963]。
    ※← [Palaeospondyloidea MOY-THOMAS 1940]。

◆パラエオスポンディルス・グンニイ (絶滅)
 Palaeospondylus gunnii Traquair 1890
   syn.Palaeospondylus gunni Woodward 1898
 *1890『On the Fossil Fishes at Achanarras Quarry, Caithness:Ramsay Heatley Traquair』。
 *1898『Outlines of Vertebrate Palæontology for Students of Zoology:Arthur Smith Woodward』。
 *2006『Is Palaeospondylus gunni a Fossil Larval Lungfish ? Insights from Neoceratodus forsteri Development:Jean Joss & Zerina Johanson』。
 *2017『Questioning Hag-Fish Affinities of the Enigmatic Devonian Vertebrate Palaeospondylus:Zerina Johanson, Moya Smith, Sophie Sanchez, Tim Senden, Kate Trinajstic & Cathrin Pfaff』。
 *2022『Morphology of Palaeospondylus Shows Affinity to Tetrapod Ancestors:Tatsuya Hirasawa, Yu-Zhi Hu, Kentaro Uesugi, Masato Hoshino, Makoto Manabe & Shigeru Kuratani』。
 *2022『The Fossil Riddle of Palaeospondylus:Jorge Mondéjar Fernández & Philippe Janvier』。
 デボン紀中期。欧州。4cm。円口類とは異なり、胸鰭と腹鰭の存在は示唆される。肺魚類の幼魚とする意見、淡水産軟骨との見解もある。トラクエアは当初から無顎類との関連を指摘、板皮類の子供ではないかとも考えるも最終的に匙を投げている「It is certainly not a Placoderm, its resemblance to a supposed 'baby Coccosteus' being entirely deceptive. The appearance of the head does remind us in a strange way of the primitive skull of Myxine, a resemblance which is rendered still more suggestive by the apparent complete absence of lower jaw or of limbs or limb-girdles. But a Myxinoid with ossified skeleton including differentiated vertebral centra is, it must be owned, a rather startling idea ! But as it requires a name in the meanwhile, I cannot think of any one more appropriate than Palæospondylus Gunnii」。長らく肺魚類(Dipterus valenciennesi Sedgwick & Murchison 1828)の幼魚ではとの解釈が続いてきたが、2022年に(進化論的に)格上げ・始四肢魚類上科との見解が示された「Despite the complete lack of teeth and dermal bones, the neurocranium of Palaeospondylus resembles those of stem-tetrapod Eusthenopteron and Panderichthys, and phylogenetic analyses place Palaeospondylus in between them. 」。

inserted by FC2 system