2015年9月2日 · Pentecopterus decorahensis, named after the ancient Greek warship, likely dominated the Ordovician ocean waters some 460 to 248 million years ago, paleontologists say. Sporting a thick head...

2014年10月20日 · In Part 6 of the Columbia Geology Tour, David Walker of the Lamont-Doherty Earth Observatory takes us back to the Ordovician period, 450 million years ago, and paints a picture of the life of an ancestor of today’s nautilus and squid.

Megalograptids are an extinct group of arthropods that dominated the Late Ordovician and Silurian periods. Sometimes referred to as a sea scorpion, Megalograptus was notable for its size, with the largest species reaching lengths of up to 750mm. It is …

The Ordovician Period in Britain was traditionally broken into Early (Tremadocian and Arenig), Middle (Llanvirn (subdivided into Abereiddian and Llandeilian) and Llandeilo) and Late (Caradoc and Ashgill) epochs. The corresponding rocks of the Ordovician System are referred to as coming from the Lower, Middle, or Upper part of the column.

2024年7月29日 · Sea scorpions (eurypterids), extinct giant aquatic arthropods, were apex predators. New research suggests that early species of the scorpion-like carcinosomatoid eurypterids, with spiny limbs, fed on trilobites and later species preferred armoured fishes.

Their offshore migration during the early stages of the GOBE was curbed by the two extinction phases, with recovery being retarded. The orthoconic cephalopods as the apex predators at that time were significantly reduced from nearly 150 species at the peak of the GOBE to some 50 species during the Hirnantian [38,50]. This slump in predator ...

2023年11月3日 · Here we report the growth trajectory of frontal appendages of the apex predator Amplectobelua symbrachiata, one of the most common radiodont arthropods from the early Cambrian Chengjiang biota (c. 520 Ma) of China.

2023年12月18日 · The orthoconic cephalopods as the apex predators at that time were significantly reduced from nearly 150 species at the peak of the GOBE to some 50 species during the Hirnantian [38, 50]. This slump in predator diversity was assigned to the destruction of the diversity of habitats for potential prey due to the early Hirnantian regression ...

2024年12月24日 · Ordovician Period, in geologic time, the second period of the Paleozoic Era. It began 485.4 million years ago and ended 443.8 million years ago. The interval was a time of intense diversification (an increase in the number of species) of marine animal life in what became known as the Ordovician radiation.

Radiodonts were among the first large predators in metazoan-dominated eco-systems that suddenly flourished near the onset of the Cambrian Series 2 (approx. 521 Ma). Their fossil record extends to the Ordovician and potentially to the Lower Devonian (from approx. 419 Ma to approx. 393 Ma) [1–11]. Mem-