Alick Walker

from Wikipedia, the free encyclopedia

Alick Donald Walker (born October 26, 1925 in Skirpenbeck , East Yorkshire , † December 4, 1999 ) was a British vertebrate paleontologist who dealt with fossil reptiles and dinosaurs.

Walker studied engineering at Cambridge until 1944, then was a radio technician in the Royal Navy and began studying geology at the University of Bristol in 1948 . After graduating in 1951, he went to the University of Newcastle , where he did research with Stanley Westoll on fossil reptiles of the Upper Triassic of Elgin (Moray) , which had been known since the 19th century and were also edited by Friedrich von Huene , but afterwards not for a long time. Most of them were poorly preserved and Walker developed a new method of making impressions of the fossils using PVC plastic that captured the anatomical details well. His dissertation from 1957 dealt mainly with Stagonolepis . In 1964 a monograph on Ornithosuchus followed , in which he also revised Eustreptospondylus . In Newcastle he became a lecturer in geology in 1954 and worked with the zoologist Alec Panchen . In 1983 he retired due to heart problems.

He returned to Elgin again and again later and published about the finds there, for example in 2002 with Michael J. Benton about Erpetosaurus . He did not publish many of his studies, but made them available to colleagues.

In the mid-1960s he turned to the Middle Triassic in the Midlands and showed that the lack of the shell limestone stage was due to the predominantly terrestrial sedimentation in Great Britain during this period (with fossil remains of basal archosaurs and rhynchosaurs ).

From the end of the 1960s, he dealt with the origins of crocodiles and birds. In 1972 he published in Nature a controversial (mostly rejected by colleagues) thesis that the ancestors of the birds were related to Crocodylomorpha (similar to Sphenosuchia ). One of his arguments was the similarity of the auditory regions. At the Archeopteryx conference in Eichstätt in 1984 he admitted that he could have been wrong and that these could be evolutionary convergences. However, he withdrew it in 1995 in an open letter to colleagues. He believed he had discovered a clear difference in the first individual feather from Archeopteryx to those of the finds with skeletal remains. The negative reactions to this letter led him to consider giving up further research at times.

After his retirement in 1983 he devoted himself to a detailed analysis of Sphenosuchus acutus from South Africa (published in a large paper in 1990) and the brain cast from Archeopteryx. He last published in 2002 on the anatomy of the brain and auditory system by Stagonolepis.

Walker named Tyrannosauroidea in 1964 .

Alwalkeria is named in his honor .

Fonts

  • Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs. Philosophical Transactions of the Royal Society of London B 248, 1964, 53-134.
  • The reptile fauna of the 'Lower Keuper' Sandstone , Geological Magazine 106, 1969, 470-476.
  • A revision of the Jurassic reptile Hallopus victor (Marsh), with remarks on the classification of crocodiles , Philosophical Transactions of the Royal Society of London B 257, 1970, 323–372.
  • with Michael Benton Palaeoecology, taphonomy, and dating of Permo-Triassic reptiles from Elgin, north-east Scotland , Palaeontology 28, 1985, 207-234
  • Evolution of the pelvis in birds and dinosaurs , in S. M: Andrews, RS Miles, AD Walker (Eds.) Problems in Vertebrate Evolution , Linnean Society Symposia, Series 4, 1977, 319-358
  • A revision of Sphenosuchus acutus Haughton, a crocodylomorph from the Elliott Formation (late Triassic or early Jurassic) of South Africa , Philosophical Transactions of the Royal Society, B, 330, 1990, 1-120

Web links

Individual evidence

  1. ^ Which he visited in Tübingen in 1954
  2. ↑ Published in Triassic reptiles from the Elgin area: Stagonolepis, Dasygnathus and their allies , Philosophical Transactions of the Royal Society of London B 244, 1961, 103-204.
  3. ↑ Benton, Walker Erpetosaurus, a crocodile-like basal archosaur from the late Triassic of Elgin, Scotland , Zoological Journal of the Linnean Society, 136, 2002, 25-47
  4. ↑ Walker New light on the origin of birds and crocodiles , Nature 237, 1972, 257-263
  5. ↑ The braincase of Archeopteryx , in MK Hecht, John H. Ostrom, G. Viohl, Peter Wellhofer The Beginnings of Birds , Friends of the Jura Museum Eichstatt, 1985, 123-134
  6. ↑ DJ Gower, Walker, Zoological J. Linnean Society, 136, 2002, 7-23
personal data
SURNAME Walker, Alick
ALTERNATIVE NAMES Walker, Alick Donald
BRIEF DESCRIPTION British paleontologist
DATE OF BIRTH October 26, 1925
PLACE OF BIRTH Skirpenbeck , East Riding of Yorkshire
DATE OF DEATH 4th December 1999