Smith A.S.,National Museum of Ireland |
Vincent P.,CNRS Center for Research on Palaeobiodiversity and Palaeoenvironments
Palaeontology | Year: 2010
The exquisitely preserved holotype of the pliosaur '. Rhomaleosaurus victor (SMNS 12478) is described from the Toarcian Posidonien-Schiefer (Upper Lias, Lower Jurassic) of Holzmaden (Baden-Württemberg), Germany. The specimen presents a novel combination of synapomorphies and unique morphometric proportions separating it from Rhomaleosaurus sensu stricto and warranting the erection of a new genus, Meyerasaurus gen. nov. Historically, the name 'Thaumatosaurus has been interchangeable with Rhomaleosaurus and is frequently associated with SMNS 12478 in the literature. However, this is an invalid taxon and cannot be reinstated. The anatomy of Meyerasaurus victor is compared in detail with other pliosaurs, and its taxonomic affinity is reviewed. M. victor belongs to the family Rhomaleosauridae and shares several anatomical characters with Rhomaleosaurus including a short and robust premaxillary rostrum (length-to-width ratio c. 1.0), parallel premaxilla-maxilla sutures anterior to the nares, vomers contacting the maxillae posterior to the internal nares, and c. 28 cervical vertebrae minus the atlas-axis. The known geographical distribution of Rhomaleosaurus, which previously extended across the German and English palaeobiogeographical zones, is reduced to the English zone as a consequence of the referral of SMNS 12478 to a new genus. This is significant because it contributes to an ongoing trend of increasing generic separation between the German and English zones, while increasing the generic diversity within the German zone itself. © The Palaeontological Association.
Dowd M.,Institute of Technology Sligo |
Carden R.F.,National Museum of Ireland
Quaternary Science Reviews | Year: 2016
The colonisation of North West Europe by humans and fauna following the Last Glacial Maximum (LGM) has been the subject of considerable discussion in recent decades and within multiple disciplines. Here we present new evidence that pushes back the date of human footfall in Ireland by up to 2500 cal BP to the Upper Palaeolithic. An assemblage of animal bones recovered from a cave in the west of Ireland during antiquarian excavations in 1903 included a butchered brown bear bone (patella) which was recently subjected to two independent radiocarbon dating processes; the resultant dates were in agreement: 12,810-12,590 cal BP and 12,810-12,685 cal BP. This find rewrites the antiquity of human occupation of Ireland and challenges the traditional paradigm that certain biota may have naturally colonised the island prior to human arrival. © 2016 Elsevier Ltd.
Benson R.B.J.,University of Cambridge |
Butler R.J.,Bayerische Staatssammlung fur Palaontologie und Geologie |
Lindgren J.,Lund University |
Smith A.S.,National Museum of Ireland
Proceedings of the Royal Society B: Biological Sciences | Year: 2010
The fossil record is our only direct means for evaluating shifts in biodiversity through Earth's history. However, analyses of fossil marine invertebrates have demonstrated that geological megabiases profoundly influence fossil preservation and discovery, obscuring true diversity signals. Comparable studies of vertebrate palaeodiversity patterns remain in their infancy. A new species-level dataset of Mesozoic marine tetrapod occurrences was compared with a proxy for temporal variation in the volume and faciès diversity of fossiliferous rock (number of marine fossiliferous formations: FMF). A strong correlation between taxic diversity and FMF is present during the Cretaceous. Weak or no correlation of Jurassic data suggests a qualitatively different sampling regime resulting from five apparent peaks in Triassic-Jurassic diversity. These correspond to a small number of European formations that have been the subject of intensive collecting, and represent 'Lagerstätten effects'. Consideration of sampling biases allows re-evaluation of proposed mass extinction events. Marine tetrapod diversity declined during the Carnian or Norian. However, the proposed end-Triassic extinction event cannot be recognized with confidence. Some evidence supports an extinction event near the Jurassic/Cretaceous boundary, but the proposed end-Cenomanian extinction is probably an artefact of poor sampling. Marine tetrapod diversity underwent a long-term decline prior to the Cretaceous-Palaeogene extinction. © 2009 The Royal Society.
Ashe P.,33 Shelton Drive |
O'Connor J.P.,National Museum of Ireland
Fauna Norvegica | Year: 2010
An update of the more significant changes affecting Part 1 of 'A World Catalogue of Chironomidae (Diptera)' is provided. These concern new taxon names, new combinations and new synonymies that were proposed, as well as omissions and errors detected, since the publication of the Catalogue at the end of 2009.
In a bit of Irish luck, archaeologists have found evidence of the Emerald Isle’s earliest known humans. A brown bear’s kneecap excavated in 1903, featuring stone tool incisions, pushes back the date that humans set foot in Ireland by as many as 2,500 years. Radiocarbon dating at two independent labs places the bone’s age between about 12,800 and 12,600 years old, say Marion Dowd of the Institute of Technology, Sligo in Ireland and Ruth Carden of the National Museum of Ireland in Dublin. Melting glaciers and milder temperatures in northwestern Europe at that time made it easier for humans to reach Ireland by boat to hunt game, at least for several weeks at a time, the researchers propose in the May 1 Quaternary Science Reviews. Until now, the oldest signs of people on Ireland came from a hunter-gatherer camp dating to about 10,290 years ago. Carden discovered the brown bear’s kneecap while studying bones that had been packed away in boxes in the 1920s, after the bones’ 1903 discovery at Ireland’s Alice and Gwendoline Cave.