Wyniki wyszukiwania

1

Phenotypic plasticity of microalgal cultures in culture collections: a geometric morphometric approach

100%

Neustupa J.

Oceanological and Hydrobiological Studies

|

2005

|

tom 34

|

nr 3

2

Evolution of marmots (Rodentia, Sciuridae): combining information on labial and lingual sides of the mandible

84%

Cardini A.

Acta Theriologica

|

2004

|

tom 49

|

nr 3

The morphology of the lingual side of the mandible was analysed in the genus Marmota. Adults from 12 of 14 living species were compared using geometric morpho- metric techniques. The information on the lingual side was then combined with that of the labial side from a previous analysis. The combined dataset is the most complete description of a marmot mandible ever used in an interspecific comparison in this genus and it represents the second morphological study ever realized that includes a large sample with all marmot species. The study confirmed the uniqueness of M. vancouverensis for mandible morphology, with atypical traits likely to have evolved in a relatively young but small population of marmots isolated on the Vancouver Island since the end of the Pleistocene (10 000-100 000 ybp), stressing the importance of a strong effort to save this species from extinction. Marmota olympus also has a distinctive mandibular trait undetected in a previous analysis using information on the lingual side only. The Olympic marmot has a longer evolutionary history but it is presently found only in the Olympic Peninsula and shares with M. vancouverensis a similar history of geographic isolation and population bottlenecks. Genetic bottlenecks might have profoundly affected marmot morphological evolution and may have increased the rate of shape change in marmot radiations. Both the analysis of the lingual side alone and the combined dataset (lingual and labial information) failed to clearly discriminate the two main marmot subgenera but the combined description of the mandible supports the similarity of the two main species (M. caligata and M. flaviventris) of the subgenus Petromarmota, and the proximity of the North American M. monax to Palaearctic marmots. Surprisingly, the analysis of the lingual side indicated that M. camtschatica and M. marmota have unusual traits for the subgenus Marmota. At least for the latter species, this finding is congruent with peculiarities in fur and parasitic relationships, and may be related to an ancient phylogenetic origin for M. marmota.

3

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Morphological disparity in Plio-Pleistocene large carnivore guilds from Italian Peninsula

67%

Meloro C.

Acta Palaeontologica Polonica

|

2011

|

tom 56

|

nr 1

Communities of large mammals exhibit changes in morphological diversity through space and time; changes that are possibly correlated to distinct aspects of the physical environment. Here, I explore shape changes in the trophic apparatus of large carnivore guilds, comparing extant communities with Quaternary ones, from peninsular Italy. Mandibular shape is quantified through geometric morphometrics and its disparity is computed for each carnivore guild. Patterns of morphospace occupation through space and time reveal that extant carnivore guilds are negatively influenced by number of artiodactyls. Very productive ecosystems show low values of morphological disparity because species tend to occupy central regions of the morphospace rather than extreme areas. Disparity of mandibular corpus shape remains relatively stable throughout the Quaternary in the large carnivore communities of the Italian peninsula. They exhibit similar values to extant guilds because the trophic apparatus did not evolved important morphological novelties. Interestingly, carnivore guilds of the late Pliocene (3.5 Ma) and early Pleistocene (0.8 Ma) show over−dispersed or random morphospace occupation because of a depleted fauna, precluding successive structural changes. The same applies for the extant European carnivore guild as a result of recent extinctions without replacement.

Ograniczanie wyników

1 Acta Palaeontologica Polonica

1 Acta Theriologica

1 Oceanological and Hydrobiological Studies

1 Cardini A.

1 Meloro C.

1 Neustupa J.

1 2011

1 2005

1 2004

Phenotypic plasticity of microalgal cultures in culture collections: a geometric morphometric approach

Evolution of marmots (Rodentia, Sciuridae): combining information on labial and lingual sides of the mandible

Morphological disparity in Plio-Pleistocene large carnivore guilds from Italian Peninsula