Talochlamys chathamensis (Hutton, 1873)
HUTTON, F. W. 1873. Catalogue of the Tertiary Mollusca and Echinodermata of New Zealand, in the collection of the Colonial Museum. Wellington, Government Printer, for Colonial Museum and Geological Survey Dept. xvi + 48 p. [p. 29]
Pecten (Chlamys) chathamensis Hutton; H. Suter, 1914, Revision of the Tertiary Mollusca of New Zealand, based on type material, Part I, plate 6, figure 6.
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«98. P. chathamensis, sp. nov. Ovato-trigonal, higher than long, equivalve, somewhat convex, regularly radiately ribbed; ribs about twenty, scaly, rounded, of equal breadth with the grooves, which are smooth; ears large, unequal, ribbed. Height, 1.3 ; length, 1.1.
Localities.— Chatham Islands; Castle Point, East Coast, Wellington; Broken River (L).» FREDERICK WOLLASTON HUTTON, 1873
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«Initially we considered that no New Zealand species was referable to Mimachlamys, but Dr Waller has pointed out (1999, pers. comm.) that the Chlamys chathamensis (Hutton) species group in New Zealand has undivided primary costae and herringbone-pattern microsculpture, and appears to belong in Mimachlamys (earliest species: ‘Chlamys’ sp. of Maxwell 1992: pl. 3g–i, Late Eocene; last record: 'Chlamys’ sp., Momoe-a-toa Shellbed, Chatham Island, basal Pliocene).»
BEU, A. G. & T. A. DARRAGH. 2001. Revision of southern Australian Cenozoic fossil Pectinidae (Mollusca: Bivalvia). Proceedings of the Royal Society of Victoria, 113: 1-205, figs. 1-67. [p. 14, 15]
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«LECTOTYPE (TM 2831) of Chlamys chathamensis, a left valve, from Trelissic Basin. Hypotypes (TM 2833), a right and a left valve from Flower-pot Harbour, Pitt Island, Chatham Islands, figured by Marwick (1928, fig. 18, 19). Holotype (TM 2834) of Chlamys compitum, a juvenile left valve.
TYPE LOCALITY: Hutton originally gave "Chatham Islands; Castle Point; Broken River (lower)" as localities for his Pecten chathamensis. The specimen selected as lectotype, probably by Hector, is from Broken River, Trelissic Basin, north Canterbury, and not from the Chatham Islands: presumably the best preserved syntype was chosen, regardless of other considerations such as tautonomy. Hutton's syntypes from the Chatham Islands and Castle Point are not preserved. The horizon of Hutton's "Broken River (lower)" locality is probably the same as that of the Fan Coral Bed, or tuffs between limestones, exposed at the junction of the Porter and Thomas Rivers (GS 239, 243, 449 in part, 3350). Age, Duntroonian (Lower Oligocene).
Chlamys compitum (Marwick) was described from Chatton (Duntroonian). ORIGINAL DESCRIPTION: "Ovato-trigonal, higher than long, equivalve, somewhat convex, regularly radiately ribbed; ribs about 20, scaly, rounded, of equal breadth with the grooves, which are smooth; ears large, unequal, ribbed. Height, 1.3; length, 1.1."
REDESCRIPTION (based on the lectotype of C. chathamensis and six topotypes from GS 239 and 243, tuffs between limestones, junction of Porter and Thomas Rivers, Trelissic Basin): Shell fairly small, both valves a little inflated; ears very unequal, with deep and wide byssal notch in anterior ear of right valve. Sculpture of right and left valve similar: 20 to 23 (mean, 21.7 on seven specimens; lectotype, 22) regular radial ribs, simple, entire, with rounded crests crossed by strong concentric scales. Interstices concave and smooth, slightly wider than the ribs. Ears sculptured by about four scaly radial riblets.
DIMENSIONS: Lectotype of C. chathalnensis – height, 31 mm; length, 29 mm.
REMARKS: Specimens of a small Chlamys are found at several localities of Duntroonian age in the South Island east coast area. All are sculptured by regular, rounded, scaly radial ribs separated by smooth, concave interspaces. In seven specimens from Trelissic Basin, including the lectotype of C. chathamensis, rib number varies from 20 to 23 (average, 22); in 28 specimens from Wharekuri (GS 476, 1341, 1288) the number varies from 20 to 27 (average, 22). Chlamys is not common at Chatton, but Finlay (1930, p. 256) stated that "enough of the adult sculpture [of the holotype of C. compitum (Marwick) from Chatton] is developed to show that the species is of the chathamensis type, and is the same as that occurring commonly in the Wharekuri greensands". Finlay (1930, pI. 46, fig. 1, 2) gave good photographs of two valves of C. compitum from Wharekuri. There is little doubt that C. chathamensis Hutton from the tuffs at Trelissic Basin is conspecific with C. compitum (Marwick) from Chatton and the Wharekuri greensands. Hutton's name is the older and therefore has preference over compitum Marwick.
A similar species of Chlamys, namely C. williamsoni Zittel (1864, p. 50, pI. 9, fig. 11, a, b, c), occurs in the Aotea Sandstone at Orotangi Cliff, Aotea Harbour (GS 6719) and Motutara Point (GS 1000) (Whaingaroan), but is distinguished from C. chathamensis by the higher average number of ribs: 11 specimens, including two of Zittel's figured specimens, both having 26 ribs (pI. 9, fig. 11, b, c), have from 24 to 27 ribs (average 26).» BOREHAM, A. U. E. 1965. A revision of F. W. Hutton's pelecypod species described in the Catalogue of Tertiary Mollusca and Echinodermata. New Zealand Geological Survey Paleontological Bulletin, 37: 1-125, pls. 1-20. [p. 21, 22]
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Chlamys chathamensis (F. W. Hutton, 1873); A. U. E. Boreham, 1965, A revision of F. W. Hutton's pelecypod species described in the Catalogue of Tertiary Mollusca and Echinodermata, plate 5, figure 6.
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«Cyclopecten compitum (p. 909).— This is not a Cyclopecten, but a nepionic Chlamys with merely the beginning of the adult sculpture. No Cyclopecten has this irregular ornament, but every Chlamys starts off more or less in this fashion. Enough of the adult sculpture is developed to show that the species is of the chathamensis type, and is the same as that occurring commonly in the Wharekuri greensands. I have one half-grown shell from Chatton which corresponds at the umbo with compitum, and is exactly the same as Wharekuri shells. As I intended describing this form, I now present the photographs I had taken (Figs. 1, 2) of Wharekuri specimens, to show the normal adult appearance of the species. It is easily distinguished by its very even and regular sculpture of stout rounded radial ribs rather distant and lamellose, the interstices 1½-2 times their width and quite smooth.»
FINLAY, H. J. 1930. Notes on Recent Papers dealing with the Mollusca of New Zealand. Transactions and Proceedings of the New Zealand Institute, 61 : 248-258, pl. 46. [p. 256]
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Chlamys compitum (Marwick); H. J. Finlay, 1930, Notes on Recent Papers dealing with the Mollusca of New Zealand, plate 46, figures 1, 2.
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