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A mysterious giant ichthyosaur from the lowermost Jurassic of Wales

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Martin J. E., Vincent P., Suan G., Sharpe T., Hodges P., Williams M., Howells C., Fischer V.

Acta Palaeontologica Polonica

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2015

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tom 60

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nr 4

Ichthyosaurs rapidly diversified and colonised a wide range of ecological niches during the Early and Middle Triassic period, but experienced a major decline in diversity near the end of the Triassic. Timing and causes of this demise and the subsequent rapid radiation of the diverse, but less disparate, parvipelvian ichthyosaurs are still unknown, notably because of inadequate sampling in strata of latest Triassic age. Here, we describe an exceptionally large radius from Lower Jurassic deposits at Penarth near Cardiff, south Wales (UK) the morphology of which places it within the giant Triassic shastasaurids. A tentative total body size estimate, based on a regression analysis of various complete ichthyosaur skeletons, yields a value of 12-15 m. The specimen is substantially younger than any previously reported last known occurrences of shastasaurids and implies a Lazarus range in the lowermost Jurassic for this ichthyosaur morphotype.

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New data on the ichthyosaur Platypterygius hercynicus and its implications for the validity of the genus

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Fischer V.

Acta Palaeontologica Polonica

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2012

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tom 57

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nr 1

The description of a nearly complete skull from the late Albian of northwestern France reveals previously unknown anatomical features of Platypterygius hercynicus, and of European Cretaceous ichthyosaurs in general. These include a wide frontal forming the anteromedial border of the supratemporal fenestra, a parietal excluded from the parietal foramen, and the likely presence of a squamosal, inferred from a very large and deep facet on the quadratojugal. The absence of a squamosal has been considered as an autapomorphy of the genus Platypterygius for more than ten years and has been applied to all known species by default, but the described specimen casts doubt on this putative autapomorphy. Actually, it is shown that all characters that have been proposed previously as autapomorphic for the genus Platypterygius are either not found in all the species currently referred to this genus, or are also present in other Ophthalmosauridae. Consequently, the genus Platypterygius must be completely revised.

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First three-dimensional skull of the Middle Triassic mixosaurid ichthyosaur Phalarodon fraasi from Svalbard, Norway

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Roberts A. J., Engelschion V. S., Hurum J. H.

Acta Palaeontologica Polonica

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2022

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tom 67

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nr 1

Ograniczanie wyników

3 Acta Palaeontologica Polonica

2 Fischer V.

1 Engelschion V. S.

1 Hodges P.

1 Howells C.

1 Hurum J. H.

1 Martin J. E.

1 Roberts A. J.

1 Sharpe T.

1 Suan G.

1 Vincent P.

1 Williams M.

1 2022

1 2015

1 2012

A mysterious giant ichthyosaur from the lowermost Jurassic of Wales

New data on the ichthyosaur Platypterygius hercynicus and its implications for the validity of the genus

First three-dimensional skull of the Middle Triassic mixosaurid ichthyosaur Phalarodon fraasi from Svalbard, Norway