Hooked

Author(s)
Leyla J. Seyfullah, Ian J. Glasspool, Jason Hilton
Abstract

Based upon anatomical evidence, Permian aged gigantopterid fossils are in general econstructed as climbing or scrambling plants. Gigantonoclea, a genus of adpressed gigantopterid foliage from the Permian of northern China, has been reported to co-occur with hook-like organs that were interpreted as indicating a scrambling/climbing habit. We reinvestigated these hook-like structures and re-evaluated the nature of the co-occurrences in context with the flora preserved in each plant-bearing fossil 'bed' in the North China sedimentary succession. New findings show that the species Gigantonoclea hallei probably climbed using specially adapted clusters of compound grappling hook-like shoots borne on the stems. This structural arrangement comprising shoots of hooks is new to the scrambling/climbing concept in gigantopterids. However, a key figured specimen previously reported as showing intermediate hook-tipped leaf morphology on a sole pinnule tip is discounted as such and is reinterpreted as a 'normal' pinnule partially hidden under sediment that results in an unusual appearance to this pinnule tip. Adaptations for climbing or scrambling based upon 'hooked leaves' observed in Gigantonoclea lagrelii are no longer supported and are reinterpreted as incompletely expanded leaves where the vernation process was interrupted. These data weaken prior interpretations of G. lagrelii as a climber/scrambler and raise doubts about the ubiquity of hooks amongst the gigantopterids as structures enabling them to climb or scramble their way through the Permian world.

Organisation(s)
Department of Palaeontology
External organisation(s)
University of Birmingham, Field Museum of Natural History
Journal
Journal of Asian Earth Sciences
Volume
83
Pages
80-90
No. of pages
11
ISSN
1367-9120
DOI
https://doi.org/10.1016/j.jseaes.2014.01.020
Publication date
04-2014
Peer reviewed
Yes
Austrian Fields of Science 2012
105117 Palaeobotany
Keywords
ASJC Scopus subject areas
Earth-Surface Processes, Geology
Portal url
https://ucrisportal.univie.ac.at/en/publications/136e4a78-bd9d-4956-9a7f-535eb7ad43c8