Wyniki wyszukiwania

1

Conflicting developmental and paleontological data: the case of the bird manus

100%

Hecht M. K., Hecht B. M.

Acta Palaeontologica Polonica

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1993

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tom 38

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nr 3-4

Phylogenetic inference is based on the distribution of characters across taxa. Characters and their states should be described in all of their complexity. The entire development of a structure should be considered to determine its significance in the search for homology and synapomorphy and for the determination of homoplasy. Simplistic description of characters often leads to comparisons of homoplasies. The pattern of development of the manus of living amniotes demonstrates a basic plan that has been retained in living birds but has been modified in theropod dinosaurs. The primitive pattern of digital and metacarpal reduction in birds (2-3-4) and other living amniotes is contrasted with manus reduction pattern of the theropods (1-2-3) based on comparative morphology. Neither digital pattern reducton is derivable from the other. The recent discovery of early dinosaurs with primitive stages of the derived reduction patterns indicates an earlier origin for birds than previously postulated. This study demonstrates the use of developmental data in distinguishing homologous structures from homoplastic structures which is important in cladistic analysis.

2

Bolyerine vertebral variation: A problem for paleoherpetology

100%

Hecht M. K., LaDuke T. C.

Acta Zoologica Cracoviensia

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1988

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tom 31

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nr 2 (11-27)

3

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Archaeopteryx and its paleoecology

100%

Hecht M. K., Tarsitano S.

Acta Palaeontologica Polonica

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1983

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tom 28

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nr 1-2

The various reptilian relationships of Archaeopteryx are reviewed. Crocodilian and theropod ancestry for Archaeopteryx and therefore birds is rejected because of the specialized morphology of both these taxa. In contrast the known morphology of certain thecodonts provides the necessary features from which the primitive avian morphology of Archaeopteryx can be derived. The origin of flight in birds is discussed within the context of the ecological setting of the Solnhofen environment. The primitive level of the flight morphology of Archaeopteryx is used to interpret the flight capabilities of these early birds.

Ograniczanie wyników

2 Acta Palaeontologica Polonica

1 Acta Zoologica Cracoviensia

3 Hecht M. K.

1 Hecht B. M.

1 LaDuke T. C.

1 Tarsitano S.

1 1993

1 1988

1 1983

Conflicting developmental and paleontological data: the case of the bird manus

Bolyerine vertebral variation: A problem for paleoherpetology

Archaeopteryx and its paleoecology