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Almatium gusevi (Chernyshev 1940): Redescription, shield-shapes; and speculations on the reproductive mode (Branchiopoda, Kazacharthra)

Kurzfassung

Almatium gusevi (Chernyshev 1940) (Branchiopoda, Kazacharthra) wird auf der Grundlage eines umfangreichen und sehr gut erhaltenen Materials aus der spättriassischen Huangshanjie-Formation des Turpan-Beckens, Xinjiang Uygur Autonome Region, China, neu beschrieben. Die »Eigenshape«-Analyse der Kopfschildformen bestätigt das Vorhandensein zweier distinkter Formen, die früher als Männchen (kleiner) und Weibchen (größer) gedeutet wurden. Neue Interpretationen führen indessen zu weiteren Spekulationen über die Reproduktion beiAlmatium gusevi, die, außer dem normalen Schlüpfen der Eier aus den Eierstöcken reproduktionsreifer Weibchen, möglicherweise auch folgendermaßen vor sich gehen kann: 1. Bildung ephippiumartiger Ruhestadien, um ein Austrocknen der Umgebung überleben zu können; 2. Entwicklung hermaphroditischer Weibchen; und 3. das Vorkommen zweier größendifferenzierter Klone in einer Population parthenogenetischer Weibchen.

Abstract

Almatium gusevi (Chernyshev 1940), a kazacharthran branchiopod, is redescribed on the basis of plentiful new and well preserved material from the Late Triassic Huangshanjie Formation in the Turpan Basin, Xinjiang Uygur Autonomous Region, China. Eigen-shape analysis of head shield-shapes confirms the occurrence in these fossils of two distinct shapes which were previously interpreted as representing males (smaller) and females (larger). New interpretations, however, lead to further speculation of the reproductive modes inA. gusevi as possibly including, in addition to hatching of normally fertilised eggs from the ovisacs of mature females: 1) formation of ephippium-like resting stages to survive ambiental drying-out; 2) development of hermaphroditic females; and 3) the possible occurrence of two electrophoretically-distinct size-differentiated clones in a population of parthenogenetic females.

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References

  1. Aladin, N. V. &Plotnikov, I. S. 1985. Microscopical study of the fluid from the maxillary gland ofDaphnia magna Straus by adaptation to water of different salinities. - Idrobiologicheskij Zhurnal21 (4): 62–65, Moscow. [In Russian]

  2. Cannon, H. G. 1925. On the segmental excretory organs of certain fresh-water ostracods. - Philosophical Transactions of the Royal Society of London, Series B214: 1–27, London.

  3. Carvalho, G. R. 1987. The clonal ecology ofDaphnia magna (Crustacea: Cladocera) II. Thermal differentiation among seasonal clones. -Journal of Animal Ecology56: 469–478, Cambridge.

  4. Carvalho, G. R. &Crisp, D. J. 1987. The clonal ecology ofDaphnia magna (Crustacea: Cladocera) I. Temporal changes in the clonal structure of a natural population. -Journal of Animal Ecology56: 453–468, Cambridge.

  5. Chen Peiji &Zhou Hanzhong 1985. A preliminary study on fossil Kazacharthra from Turpan Basin. - Kexue Tonabào30 (7): 950–954.

  6. Chernyshev, B. I. 1940. Mesozoic Branchiopoda from Turkestan and Transbaikal. - Akademiya Nauk Ukrainskoj SSR, Geologicheskij Zhurnal7 (3): 5–43, Kiev. [In Russian, with English summary.]

  7. Fryer, G. 1987. A new classification of the branchiopod Crustacea. - Zoological Journal of the Linnean Society, London91: 358–383, London.

  8. — 1988. Studies on the functional morphology and biology of Notostraca (Crustacea: Branchiopoda). Philosophical Transactions of the Royal Society of London, Series B321: 27–124, London.

  9. Grasser, J. 1933. Die exkretonschen Organe vonTriops (Apus) cancriformis Bosc. - Zeitschrift für Wissenschaftliche Zoologie144: 317–362, Leipzig.

  10. Karmishina, G. I. &Neustrueva, I. J. 1987. Freshwater Ostracoda developmental history in the Eurasian Mesozoic and Cainozoic. - Voprosy mikropaleontologii29: 127–140, Moscow.

  11. Linder, F. 1952. Contributions to the morphology and taxonomy of the Branchiopoda Notostraca with special reference to North American species. - Proceedings of the United States National Museum of Natural History102 (3291): 1–54, Washington, D.C.

  12. Lohmann, G. P. 1983. Eingshape analysis of microfossils: a general morphometric procedure for describing changes in shape. -Mathematical Geology15: 659–672, New York.

  13. Novozhilov, N. I. 1957. Un nouvel ordre d’arthropodes particuliers: Kazacharthra du Lias des Monts Ketmen (Kazakhstan S. E., U.R.S.S.). - Bulletin de la Société géologique de France,6 série7: 171–184, Paris.

  14. — 1959. Position systématique des Kazacharthra (Arthropodes) d’après de nouveau matériaux des monts Ketmen et Sajkan (Kazakhstan), S. E. et N. E. - Bulletin de la Société géologique de France,7 série1:265–269, Paris.

  15. — 1960. Subclass Gnathostraca. - [In:]Orlov, Yu. A. (Ed.) Basic Paleontology Volume 8: 216–253. Science-Technical Press, Moscow. [In Russian]

  16. Rossi, V. &Menozzi, P. 1990. The clonal ecology ofHeterocypris incongruens (Ostracoda). - Oikos57 (3): 388–398, Copenhagen.

  17. Smirnov, N. N. 1970. Cladocera (Crustacea) from the Permian of Eastern Kazakhstan. - Paleontologiches- kij Zhurnal1970 (3): 95–100, Moscow. [In Russian]

  18. Tasch, P. 1969. Branchiopoda. - [In:]Moore, R. C. (ed.) Treatise on Invertebrate Paleontology, Part R, Arthropoda 4, Crustacea (except Ostracoda), Myriapoda-Hexapoda: R 128-R 191, Geological Society of America, New York, and the University of Kansas Press, Lawrence, Kansas.

  19. Zahn, C. I. &Roskies, R. Z. 1972. Fourier descriptors for plane closed curves. - Institute of Electrical and Electronic Engineers Transactions on ComputersC21: 269–281, Lawrence, Kansas.

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Correspondence to Ken G. McKenzie or Chen Pei-Ji or Stefan Majoran.

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McKenzie, K.G., Pei-Ji, C. & Majoran, S. Almatium gusevi (Chernyshev 1940): Redescription, shield-shapes; and speculations on the reproductive mode (Branchiopoda, Kazacharthra). Paläont. Z. 65, 305–317 (1991). https://doi.org/10.1007/BF02989846

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Keywords

  • Abdominal Segment
  • Reproductive Mode
  • Parthenogenetic Female
  • Shell Gland
  • Thoracic Limb