The evolution and distribution of fishes / by John Muirhead Macfarlane.

  • John Muirhead Macfarlane
Date:
1923
Catalogue details

Licence: In copyright

Credit: The evolution and distribution of fishes / by John Muirhead Macfarlane. Source: Wellcome Collection.

    145/584 page 131
    A somewhat related fish-fauna is that from Scaumenac Bay and other parts of Canada, but so far as it is now known, it did not include such gigantic forms as Dinichthys and Titanichthys. Eastman’s condensed list (89: 16, 17) is as varied as it is suggestive. In North America, as in Europe, the fossilized fish- fauna of the Upper Devonian is nearly always associated with beds that are rich in eurypterids, in phyllopods, in highly evolved scorpions and myriapods, in a characteristic mollusc, and in finely preserved specimens of ferns and lepidodendroid plants. These have been described or re- ferred to by Dawson, Newberry, Claypole (op. cit. p. 342), Patten (70:377) and others. More than passing mention however should be made of “a freshwater mollusc.” Originally named Anodon jukesii by Edward Forbes, its history and biological environment have been ably traced by R. B. Newton (90:245) who named it Archanodon jukesii. He points out that Forbes found with it, at Knock- topher in Ireland, remains of the eurypterid Pterygotus, of the fish Holoptychius, also the Upper Old Red plants Cyclopteris, Archaeopteris (or Palaeopteris) hibernicus, Lepidodendron, and Stigmaria. Subsequently commented on by Baily, Jukes, Hull, and Boyd Dawkins, it was by the last compared with Cypricardites catskillensis a< closely allied form from Chenango County, New York State. In Ireland as in America similar environal conditions evidently prevailed, for he writes: “In Ireland the mollusc occurs with Palaeopteris hibernica etc., Coccosteus etc., and Eurypterus scoulerif etc; in Northumberland with Uloden- dron ornatissimum and Catamites/ and in America A. cats- killensis, the close ally of the British species, is found in company with plant and fish remains (Holonema rugo- sum)Here then we have a glimpse of a freshwater biological grouping that must have been more or less con- tinuous from England to America. So he concludes: “All these facts demonstrate that the genus Archanodon was of lacustrine or fluviatile origin, and that the deposition of the beds containing it, whether in England, Ireland or America must have been regulated
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