Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Porkuni village

Sortuj według:

Ogranicz wyniki do:

Artykuł dostępny w postaci pełnego tekstu - kliknij by otworzyć plik

Concentration of juvenile and small cephalopods in the Hirnantian cherts [Late Ordovician] of Porkuni, Estonia

100%

Kroger B.

Acta Palaeontologica Polonica

2007

tom 52

nr 3

The quarry in the north Estonian village of Porkuni provides a succession of shallow−water limestones and cherts spanning the Ashgillian Normalograptus? extraordinarius graptolite Biozone. This interval comprises the initial pulse of the end−Ordovician extinction. The succession of Porkuni contains abundant and extraordinarily well−preserved fossils. 71 cephalopod specimens were extracted from these strata at Porkuni. Many of these specimens are fragments of juvenile shells or small adults. The embryonic shells of the cephalopods are usually preserved and provide insight into their early ontogeny. The faunal composition is considered as autochthonous and reflects a “palaeo−nursery” in a Hirnantian reef environment. The collected specimens represent twelve genera and four orders. Small oncoceridans and orthoceridans dominate the association. The rate of endemism is very high, since only two genera found in Porkuni, are known from outside Baltoscandia. The new genera Parvihebetoceras, Pomerantsoceras, Porkunioceras, and the new species Parvihebetoceras wahli, Pomerantsoceras tibia, Porkunioceras tuba, and Strandoceras orvikui are erected.

Ograniczanie wyników

1 Acta Palaeontologica Polonica

1 Kroger B.

1 2007

Wyniki wyszukiwania

Concentration of juvenile and small cephalopods in the Hirnantian cherts [Late Ordovician] of Porkuni, Estonia