Marine reptiles from the Lower Cretaceous of South Australia: elements of a high-latitude cold-water assemblage
The definitive version is available at onlinelibrary.wiley.com The Lower Cretaceous rocks of South Australia have yielded a diverse marine reptile assemblage of up to five families of plesiosaur (including a new cryptoclidid or cimoliasaurid, indeterminate elasmosaurids, a possible polycotylid, rhom...
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Online Access: | http://hdl.handle.net/2440/23716 https://doi.org/10.1111/j.1475-4983.2006.00569.x |
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ftunivadelaidedl:oai:digital.library.adelaide.edu.au:2440/23716 2023-05-15T13:34:44+02:00 Marine reptiles from the Lower Cretaceous of South Australia: elements of a high-latitude cold-water assemblage Kear, Benjamin Philip School of Earth and Environmental Sciences 2006 http://hdl.handle.net/2440/23716 https://doi.org/10.1111/j.1475-4983.2006.00569.x en eng Blackwell Publishing Palaeontology, 2006; 49 (4):837-856 0031-0239 http://hdl.handle.net/2440/23716 doi:10.1111/j.1475-4983.2006.00569.x Plesiosauria Ichthyosauria South Australia Lower Cretaceous high latitudes cold climates Journal article 2006 ftunivadelaidedl https://doi.org/10.1111/j.1475-4983.2006.00569.x 2023-02-06T06:57:42Z The definitive version is available at onlinelibrary.wiley.com The Lower Cretaceous rocks of South Australia have yielded a diverse marine reptile assemblage of up to five families of plesiosaur (including a new cryptoclidid or cimoliasaurid, indeterminate elasmosaurids, a possible polycotylid, rhomaleosaurids, and pliosaurid) and one family of ichthyosaur (ophthalmosaurid). Other common associated vertebrates include chimaerids and osteichthyans. Sharks, dipnoans and dinosaurs are uncommon and marine turtles are notably absent. The main fossil-producing strata belong to the Lower Aptian–Lower Albian Bulldog Shale although the Upper Albian Oodnadatta Formation has produced isolated elements. Both these units comprise finely laminated shaly mudstones and claystones deposited in a transgressive shallow coastal, epicontinental marine environment. Estimates of palaeolatitude place South Australia between 60_ and 70_S, in the late Early Cretaceous. Sedimentary structures (including lonestone boulders and glendonites), fossils, isotope data and climatic modelling also indicate that seasonally cool–cold conditions (possibly with winter freezing) prevailed during deposition of the Bulldog Shale. This contrasts markedly with climate regimes typically tolerated by modern aquatic reptiles but suggests that some of the South Australian Mesozoic taxa may have possessed adaptations (including elevated metabolic levels and / or annual migration) to cope with low temperatures. A high proportion of juvenile plesiosaur remains in the Bulldog Shale might also indicate that nutrient-rich cold-water coastal habitats functioned as both ‘safe calving grounds’ and refuges for young animals prior to their entering the open sea as adults. The occurrence of plesiosaurs and ichthyosaurs in the high-latitude Lower Cretaceous of southern Australia, along with plesiosaurs and mosasaurs in the Upper Cretaceous of South America, Antarctica, New Zealand and the Chatham Islands, demonstrates that Mesozoic marine reptiles utilized southern ... Article in Journal/Newspaper Antarc* Antarctica Antarctica New Zealand The University of Adelaide: Digital Library New Zealand Palaeontology 49 4 837 856 |
institution |
Open Polar |
collection |
The University of Adelaide: Digital Library |
op_collection_id |
ftunivadelaidedl |
language |
English |
topic |
Plesiosauria Ichthyosauria South Australia Lower Cretaceous high latitudes cold climates |
spellingShingle |
Plesiosauria Ichthyosauria South Australia Lower Cretaceous high latitudes cold climates Kear, Benjamin Philip Marine reptiles from the Lower Cretaceous of South Australia: elements of a high-latitude cold-water assemblage |
topic_facet |
Plesiosauria Ichthyosauria South Australia Lower Cretaceous high latitudes cold climates |
description |
The definitive version is available at onlinelibrary.wiley.com The Lower Cretaceous rocks of South Australia have yielded a diverse marine reptile assemblage of up to five families of plesiosaur (including a new cryptoclidid or cimoliasaurid, indeterminate elasmosaurids, a possible polycotylid, rhomaleosaurids, and pliosaurid) and one family of ichthyosaur (ophthalmosaurid). Other common associated vertebrates include chimaerids and osteichthyans. Sharks, dipnoans and dinosaurs are uncommon and marine turtles are notably absent. The main fossil-producing strata belong to the Lower Aptian–Lower Albian Bulldog Shale although the Upper Albian Oodnadatta Formation has produced isolated elements. Both these units comprise finely laminated shaly mudstones and claystones deposited in a transgressive shallow coastal, epicontinental marine environment. Estimates of palaeolatitude place South Australia between 60_ and 70_S, in the late Early Cretaceous. Sedimentary structures (including lonestone boulders and glendonites), fossils, isotope data and climatic modelling also indicate that seasonally cool–cold conditions (possibly with winter freezing) prevailed during deposition of the Bulldog Shale. This contrasts markedly with climate regimes typically tolerated by modern aquatic reptiles but suggests that some of the South Australian Mesozoic taxa may have possessed adaptations (including elevated metabolic levels and / or annual migration) to cope with low temperatures. A high proportion of juvenile plesiosaur remains in the Bulldog Shale might also indicate that nutrient-rich cold-water coastal habitats functioned as both ‘safe calving grounds’ and refuges for young animals prior to their entering the open sea as adults. The occurrence of plesiosaurs and ichthyosaurs in the high-latitude Lower Cretaceous of southern Australia, along with plesiosaurs and mosasaurs in the Upper Cretaceous of South America, Antarctica, New Zealand and the Chatham Islands, demonstrates that Mesozoic marine reptiles utilized southern ... |
author2 |
School of Earth and Environmental Sciences |
format |
Article in Journal/Newspaper |
author |
Kear, Benjamin Philip |
author_facet |
Kear, Benjamin Philip |
author_sort |
Kear, Benjamin Philip |
title |
Marine reptiles from the Lower Cretaceous of South Australia: elements of a high-latitude cold-water assemblage |
title_short |
Marine reptiles from the Lower Cretaceous of South Australia: elements of a high-latitude cold-water assemblage |
title_full |
Marine reptiles from the Lower Cretaceous of South Australia: elements of a high-latitude cold-water assemblage |
title_fullStr |
Marine reptiles from the Lower Cretaceous of South Australia: elements of a high-latitude cold-water assemblage |
title_full_unstemmed |
Marine reptiles from the Lower Cretaceous of South Australia: elements of a high-latitude cold-water assemblage |
title_sort |
marine reptiles from the lower cretaceous of south australia: elements of a high-latitude cold-water assemblage |
publisher |
Blackwell Publishing |
publishDate |
2006 |
url |
http://hdl.handle.net/2440/23716 https://doi.org/10.1111/j.1475-4983.2006.00569.x |
geographic |
New Zealand |
geographic_facet |
New Zealand |
genre |
Antarc* Antarctica Antarctica New Zealand |
genre_facet |
Antarc* Antarctica Antarctica New Zealand |
op_relation |
Palaeontology, 2006; 49 (4):837-856 0031-0239 http://hdl.handle.net/2440/23716 doi:10.1111/j.1475-4983.2006.00569.x |
op_doi |
https://doi.org/10.1111/j.1475-4983.2006.00569.x |
container_title |
Palaeontology |
container_volume |
49 |
container_issue |
4 |
container_start_page |
837 |
op_container_end_page |
856 |
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1766056670055628800 |