منابع مشابه
Humble origins for a successful strategy: complete enrolment in early Cambrian olenellid trilobites.
Trilobites are typified by the behavioural and morphological ability to enrol their bodies, most probably as a defence mechanism against adverse environmental conditions or predators. Although most trilobites could enrol at least partially, there is uncertainty about whether olenellids-among the most phylogenetically and stratigraphically basal representatives-could perform this behaviour becau...
متن کاملControls on Gut Phosphatisation: The Trilobites from the Weeks Formation Lagerstätte (Cambrian; Utah)
Despite being internal organs, digestive structures are frequently preserved in Cambrian Lagerstätten. However, the reasons for their fossilisation and their biological implications remain to be thoroughly explored. This is particularly true with arthropods--typically the most diverse fossilised organisms in Cambrian ecosystems--where digestive structures represent an as-yet underexploited alte...
متن کاملPhosphatised olenid trilobites and associated fauna from the Upper Cambrian of Västergötland, Sweden
Secondarily phosphatised olenid trilobites from organic−rich limestones (orsten) in the Furongian (Upper Cambrian) of Västergötland, south−central Sweden, are described and illustrated. All trilobites originate from the Peltura scara− baeoides Zone and were collected on the western slope of Kinnekulle. Only the dorsal exoskeletons have become second− arily phosphatised, and the ventral appendag...
متن کاملStrength in numbers: High phenotypic variance in early Cambrian trilobites and its evolutionary implications.
Analysis of the degree of intraspecific morphological polymorphism during the evolutionary history of trilobites using an informatic approach(1) provides striking evidence of a long-suspected but previously unsubstantiated pattern: degrees of polymorphism are markedly higher in phylogenetically basal, stratigraphically early species. This unequivocal pattern prompts further exploration of the r...
متن کاملbiostratigraphy late early cambrian - late cambrian successions in kamar siah section (southeast kerman) on the basis of trilobites
cambrian sediments are widely exposed in the kerman province. parts of these deposits are containing trilobite fossils. one of the suitable areas for paleontological studies is kamar siah section. this section located about 60 km north east of kerman. these sediments have 200 m thickness with fossil invertebrates of trilobites, brachiopod, gastropods and stromatolite which includes kuhbanan and...
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 1916
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.2.2.101