A Remarkable Nautiloid from the Second Value of New Mexico

A Remarkable Nautiloid from the Second Value of New Mexico

MEMOIR 21 PART I Botryceras, A Remarkable Nautiloid from the Second Value of New Mexico PART II An Endoceroid from the Mohawkian of Quebec PART III Endoceroids from the Canadian of Alaska PART IV A Chazyan Cephalopod Fauna from Alaska by ROUSSEAU H. FLOWER 1968 STATE BUREAU OF MINES AND MINERAL RESOURCES NEW MEXICO INSTITUTE OF MINING AND TECHNOLOGY CAMPUS STATION SOCORRO, NEW MEXICO NEW MEXICO INSTITUTE OF MINING & TECHNOLOGY Stirling A. Colgate, President STATE BUREAU OF MINES AND MINERAL RESOURCES Frank E. Kottlowski, Acting Director THE REGENTS MEMBERS Ex OFFICIO THE HONORABLE DAVID F. CARGO ........................ Governor of New Mexico LEONARD DELAYO .................................... Superintendent of Public Instruction APPOINTED MEMBERS WILLIAM G. ABBOTT ................................................................ Hobbs EUGENE L. COULSON, M.D. ................................................................. Socorro THOMAS M. CRAMER ...................................................................... Carlsbad STEVE S. TORRES, JR. ....................................................................................... Socorro RICHARD M. ZIMMERLY ................................................................. Socorro Published July 31, 1968 For sale by the New Mexico Bureau of Mines & Mineral Resources Campus Station, Socorro, N. Mex. 87801—Price $2.00 Contents Page PART I ABSTRACT ..................................................................................................................................................... 3 INTRODUCTION ........................................................................................................................................ 3 Genus Botryceras Flower, n. gen. ................................................................................................. 4 Botryceras enigma Flower, n. sp. ........................................................................................... 4 PART II ABSTRACT ....................................................................................................................................................... 9 INTRODUCTION ........................................................................................................................................ 9 Cameroceras alternatum Flower, n. sp. ............................................................................ 9 PART III ABSTRACT ..................................................................................................................................................... 13 INTRODUCTION ......................................................................................................................................... 13 Genus Kugeloceras Flower, n. gen. ........................................................................................ 13 Kugeloceras obtusum Flower, n. sp. ................................................................................ 13 FAMILY YORKOCERATIDAE Flower, n. fam. .............................................................................. 14 Genus Yorkoceras Flower, n. gen. .......................................................................................... 14 Yorkoceras discordium Flower, n. sp. .......................................................................... 15 Genus Sewardoceras Flower, n. gen. ...................................................................................... 15 Sewardoceras tellerense Flower, n. sp. ........................................................................... 15 Sewardoceras? sp. ................................................................................................................... 15 Genus Telleroceras Flower, n. gen. ........................................................................................ 16 Telleroceras undulatum Flower, n. sp. ........................................................................... 16 PART IV ABSTRACT ..................................................................................................................................................... 21 INTRODUCTION ......................................................................................................................................... 21 Genus Franklinoceras ..................................................................................................... 21 Franklinoceras tellerense Flower, n. sp. ......................................................................... 21 Genus Proteoceras ......................................................................................................... 22 Proteoceras obliquum Flower, n. sp. ............................................................................... 22 Proteoceras tubulare Flower, n. sp. ................................................................................ 22 COLLECTIVE REFERENCES .................................................................................................................. 23 PLATES ............................................................................................................................................................ 25 INDEX ............................................................................................................................................................. 36 PART I BOTRYCERAS, A REMARKABLE NAUTILOID FROM THE SECOND VALUE OF NEW MEXICO Abstract Botryceras enigma is an apparent endoceroid cephalopod vided anteriorly into two groups. No forms or close affinities known from a remarkable endosiphuncle in which sheaths are are known, but the structure indicates tentative assignment sparingly developed or preserved and the simple cones ter- to the order Endoceratida. minate in a group of centrate tubes, rather irregular, but di- Introduction The form here described is a long, straight, very slender buckle limestone of Oklahoma in association with Ceratopea endosiphuncle, partly fibrous in texture and unusually rich unguis (fide Yochelson). Troedssonella itself is thus far in carbonaceous material peripherally, showing one good en- known only from the upper Orthoceras limestone where it dosiphosheath, with a surface faintly angled in cross section, occurs (Jaanusson, 196o) in the Folkeslunda limestone of the terminating centrally in a group of tubes that lack dia- late Lasnamagian. phragms. Only a single weathered endosiphuncle is known. There is seemingly a considerable stratigraphic gap be- The form is so remarkable that its description was delayed for tween the Troedssonellidae and the Narthecoceratidae. The several years in the hope of obtaining additional material, a Narthecoceratidae are recognized as containing two subfam- hope that has so far remained unfulfilled. Indeed, the possi- ilies. The Narthecoceratinae, which has a central tube, is bility that this could be some other organism than a cepha- represented by Narthecoceras, which appears in the Red lopod was considered, a possibility that has found no support River faunas, apparently simultaneously from Greenland to and is, indeed, opposed by the presence of one well-preserved western Texas but continues into the early Middle Silurian conical sheath. Though this form has the aspect of an endoc- of the James Bay lowland, and Calhounoceras, a genus known eroid endosiphuncle, it must be noted that its abundant car- as yet only from the Cape Calhoun beds of Greenland. The bonaceous material is peculiar; it is not impossible that more subfamily Donacoceratinae contains forms in which the tube material may show it to belong to some other group, perhaps is strongly eccentric, with cones short on the side to which the the Michelinoceratida. Investigations still unpublished tube is closest but greatly extended forward on the opposite (Flower, in press) showed that Narthecoceras, which every- side. Here are placed the genera Tasmanoceras of the Ordo- one including the writer had accepted as an endoceroid, be- vician of Tasmania, formerly assigned to the Endoceratida, longs instead to the order Michelinoceratida. This was first and Donacoceras, known from the early Middle Silurian of indicated by Silurian material showing that the necks are east-central Canada. short, the rings thin and homogenous, and cameral deposits With these matters in mind, the peculiar texture and fi- are present, all features alien to the order Endoceratida. Fur- brous composition of the endosiphuncle of Botryceras may ther examination showed that though the siphuncle possesses indicate some other affinities in the Cephalopoda than the a large, heavy endosiphuncle with seemingly simple endo- order Endoceratida, but the genus is tentatively assigned cones, it differs materially in habit from endosiphuncles of there inasmuch as there is no clear evidence of its connection associated Endoceratida in Red River faunas: growth incre- with any other cephalopod lineage. ments are much thinner, sheaths are poorly differentiated, Oddly, one genus has been described as agreeing with Bot- microstructure reveals a peculiar fibrous texture alien to that ryceras in having several subcentral tubes grouped closely of the Endoceratida, and the tube shows peculiarities of some together. This is the genus Tallinoceras Balashov (196o), complexity and variety, the most remarkable of which is the based upon T. lasnamense, from beds in the Ordovician sup- development of diaphragms from which "brackets" extend posedly equivalent to the Echinosphaerites limestone of the forward and are, in some

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