CSIRO Publishing blank image blank image blank image blank imageBooksblank image blank image blank image blank imageJournalsblank image blank image blank image blank imageAbout Usblank image blank image blank image blank imageShopping Cartblank image blank image blank image You are here: Journals > Australian Journal of Zoology   
Australian Journal of Zoology
Journal Banner
  Evolutionary, Molecular and Comparative Zoology
 
blank image Search
 
blank image blank image
blank image
 
  Advanced Search
   

Journal Home
About the Journal
Editorial Structure
Contacts
Content
Online Early
Current Issue
Just Accepted
All Issues
Special Issues
Sample Issue
For Authors
General Information
Author Instructions
Submit Article
Scope
Open Access
Awards and Prizes
For Referees
Referee Guidelines
Review an Article
Annual Referee Index
For Subscribers
Subscription Prices
Customer Service
Print Publication Dates

blue arrow e-Alerts
blank image
Subscribe to our Email Alert or RSS feeds for the latest journal papers.

red arrow Connect with us
blank image
facebook twitter LinkedIn

 

Article     |     Next >>   Contents Vol 50(1)

A review of terrestrial mammalian and reptilian carnivore ecology in Australian fossil faunas, and factors influencing their diversity: the myth of reptilian domination and its broader ramifications

S. Wroe

Australian Journal of Zoology 50(1) 1 - 24
Published: 16 April 2002

Abstract

The notion that Australia’s large, terrestrial carnivore faunas of the middle Tertiary to Pleistocene were dominated by reptiles has gained wide acceptance in recent decades. Simple but sweeping hypotheses have been developed seeking to explain this perceived ecological phenomenon. However, a review of the literature does not support these interpretations, which are based on largely speculative and, in many cases, clearly erroneous assumptions. Few size estimates of fossil reptilian taxa are based on quantitative methodology and, regardless of method, most are restricted to maximum dimensions. For species of indeterminate growth, this practice generates misleading perceptions of biological significance. In addition to misconceptions with respect to size, much speculation concerning the lifestyles of large extinct reptiles has been represented as fact. In reality, it has yet to be demonstrated that the majority of fossil reptiles underpinning the story of reptilian domination were actually terrestrial. No postcranial evidence suggests that any Australian mekosuchine crocodylian was less aquatic than extant species, while a semi-aquatic habitus has been posited for madtsoiid snakes and even the giant varanid, Megalania. Taphonomic data equivocally supports the hypothesis that some Australian mekosuchines were better adapted to life on land than are most extant crocodylians, but still semi-aquatic and restricted to the near vicinity of major watercourses. On the other hand, the accelerating pace of discovery of new large mammalian carnivore species has undermined any prima facie case for reptilian supremacy regarding pre-Pleistocene Australia (that is, if species richness is to be used as a gauge of overall impact). However, species abundance and consumption, not richness, are the real measures. On this basis, even in Pleistocene Australia, where species richness of large mammalian carnivores was relatively low, available data expose the uncommon and geographically restricted large contemporaneous reptiles as bit players. In short, the parable of a continent subject to a Mesozoic rerun, wherein diminutive mammals trembled under the footfalls of a menagerie of gigantic ectotherms, appears to be a castle in the air. However, there may be substance to some assertions. Traditionally, erratic climate and soil-nutrient deficiency have been invoked to explain the perception of low numbers or relatively small sizes of fossil mammalian carnivore taxa in Australia. But these arguments assume a simple and positive relationship between productivity, species richness and maximum body mass and either fail to recognise, or inappropriately exclude, other factors. Productivity has undoubtedly played a role, but mono-factorial paradigms cannot account for varying species richness and body mass among Australia’s fossil faunas. Nor can they explain differences between Australian fossil faunas and those of other landmasses. Other factors that have contributed include sampling bias, a lack of internal geographic barriers, competition with large terrestrial birds and aspects of island biogeography unique to Australia, such as landmass area and isolation, both temporal and geographic.



Full text doi:10.1071/ZO01053

© CSIRO 2002

blank image
Subscriber Login
Username:
Password:  

 
PDF (286 KB) $25
 Export Citation
 Print
  
    
Legal & Privacy | Contact Us | Help

CSIRO

© CSIRO 1996-2015