Skip to content Skip to navigation

Article: Comparative crystallography suggests maniraptoran theropod affinities for latest Cretaceous European ‘geckoid’ eggshell

Papers in Palaeontology - Volume 6 Issue 2 - Cover
Publication: Palaeontology
Volume: 6
Part: 2
Publication Date: May 2020
Page(s): 265 292
Author(s): Seung Choi, Miguel Moreno‐Azanza, Zoltán Csiki‐Sava, Edina Prondvai, and Yuong‐Nam Lee
DOI: 10.1002/spp2.1294
Addition Information

How to Cite

CHOI, S., MORENO‐AZANZA, M., CSIKI‐SAVA, Z., PRONDVAI, E., LEE, Y. 2020. . Papers in Palaeontology, 6, 2, 265-292. DOI: /doi/10.1002/spp2.1294

Author Information

  • Seung Choi - School of Earth & Environmental Sciences Seoul National University Seoul 08826 South Korea
  • Miguel Moreno‐Azanza - Geobiotec, Departamento de Ciências da Terra Universidade Nova de Lisboa Caparica 2829‐526 Portugal
  • Miguel Moreno‐Azanza - Espaço Novapaleo & Geophysics Museu de Lourinhã Lourinhã 2530‐158 Portugal
  • Zoltán Csiki‐Sava - Faculty of Geology & Geophysics University of Bucharest Bucharest 010041 Romania
  • Edina Prondvai - Department of Biology Ghent University Ghent 9000 Belgium
  • Yuong‐Nam Lee - School of Earth & Environmental Sciences Seoul National University Seoul 08826 South Korea

Publication History

  • Issue published online: 25 April 2020
  • Manuscript Accepted: 31 October 2019
  • Manuscript Received: 15 April 2019

Funded By

Fundação para a Ciência e a Tecnologia. Grant Numbers: PTDC/CTA‐PAL/31656/2017, SFRH/BPD/113130/2015
National Research Foundation of Korea. Grant Number: 2019R1A2B5B02070240
Bijzonders Onderzoeksfonds (BOF) – Universiteit Gent. Grant Number: 01P12815
MTA‐MTM‐ELTE Research Group for Paleontology

Online Version Hosted By

Wiley Online Library
Get Article: Wiley Online Library [Pay-to-View Access] |

Abstract

Thin fossil eggshell from Upper Cretaceous deposits of Europe, characterized by nodular ornamentation similar to modern gekkotan eggshell, has mostly been interpreted as gekkotan (=‘geckoid’) in origin. However, in some cases, as for the oogenus Pseudogeckoolithus, a theropod affinity has also been suggested. The true affinity of these fossil ‘geckoid’ eggshells has remained controversial due to the absence of analytical methods for identifying genuine gecko eggshell in the fossil record. In this study, we apply electron backscatter diffraction (EBSD) analysis to latest Cretaceous European ‘geckoid’ (including Pseudogeckoolithus) eggshell, in comparison with modern gekkotan and theropod (avian) eggshell. We found that Pseudogeckoolithus has a definite theropod eggshell‐like crystallographic configuration, in clear contrast to that seen in modern ‘gecko eggshells’. Furthermore, the crystallography of the nodular ornamentation in Pseudogeckoolithus is similar to that seen in megapode eggshell, but different from that of gecko eggshell, despite superficial morphological similarity. The remarkable morphological similarities between Pseudogeckoolithus and modern gecko eggshells are thus convergent, and the ‘gekkotan affinity’ hypothesis can be dismissed for Pseudogeckoolithus. This study provides a template for differentiating true gekkotan from dinosaurian eggshells in the fossil record. The potential functional significance of eggshell ornamentation, lost in most modern birds, requires further study, and experimental zoological approach may shed light on this issue. Finally, the present results suggest caution about the dangers of using potentially homoplastic eggshell characters in eggshell parataxonomy.

PalAss Go! URL: http://go.palass.org/kxh | Twitter: Share on Twitter | Facebook: Share on Facebook | Google+: Share on Google+