-40%

RARE HIRNANTIA FAUNA.BRIOZOA Ralfina and Helopora.ORDOVICIAN.PORTUGAL.nº2PT

$ 10.03

Availability: 100 in stock
  • All returns accepted: Returns Accepted
  • Refund will be given as: Money Back
  • Restocking Fee: No
  • Return shipping will be paid by: Buyer
  • Item must be returned within: 30 Days

    Description

    <<  EXCELLENT AND  VERY RARE FOSSILS.   PLATE
    WHIT HIRNANTIA FAUNA .  BRIOZOA >>
    Ralfina lusitanica, helopora and
    another rare, undetermined bryozoan.
    Upper Ordovician (hirnantian fauna) .Queixoperra Member of the Cabeço de Peao Formation. Amendoa-Maçao Area . Portugal.
    EXCELLENT and very rare fossil
    The
    Hirnantian
    is the seventh and final internationally recognized stage of the ordovician period of the paleozoic era. It was of short duration, lasting about 1.9 million years, from 445.2 ± 1.4 to 443.8 ± 1.5 Ma (million years ago). The early part of the Hirnantian was characterized by cold temperatures, major glaciation , and a severe drop in sea level. In the latter part of the Hirnantian, temperatures rose, the glaciers melted, and sea level returned to the same or to a slightly higher level than it had been prior to the glaciation.
    Most scientists believe that this climatic oscillation caused the major extinction event that took place during this time. In fact, the Hirnantian (also known as the End Ordovician and the ordovician-silurian) mass extinction event represents the second largest such event in geologic history. Approximately 85% of marine (sea-dwelling) species died. Only the End permian mass extinction
    was larger. Unlike many smaller extinction events, however, the long-term consequences of the End Ordovician event were relatively small. Following the climatic oscillation, the climate returned to its previous state, and the species that survived soon (within two or three million years) evolved into species very similar to the ones that existed before.
    Size plate:  12 x 6 x 2 cm
    weight: 120 g.
    <>>
    100% natural
    Excellent detailing
    Expenses shipment
    :
    For Europe: 
    For USA:  .
    ===========================================================================
    We combine shipping: