First evidence of convergent lifestyle signal in reptile skull roof microanatomy

  title={First evidence of convergent lifestyle signal in reptile skull roof microanatomy},
  author={Roy Ebel and Johannes M{\"u}ller and Till Ramm and Christy A. Hipsley and Eli Amson},
  journal={BMC Biology},
Background The study of convergently acquired adaptations allows fundamental insight into life’s evolutionary history. Within lepidosaur reptiles—i.e. lizards, tuatara, and snakes—a fully fossorial (‘burrowing’) lifestyle has independently evolved in most major clades. However, despite their consistent use of the skull as a digging tool, cranial modifications common to all these lineages are yet to be found. In particular, bone microanatomy, although highly diagnostic for lifestyle, remains… 

Phylogenetic history influences convergence for a specialized ecology: comparative skull morphology of African burrowing skinks (Squamata; Scincidae)

Although there was broad convergence in both shape and qualitative traits, phylogenetic history played a large role and much of this convergence was produced by different anatomical changes, implying different developmental pathways or lineage-specific constraints.

Convergence, divergence, and macroevolutionary constraint as revealed by anatomical network analysis of the squamate skull, with an emphasis on snakes

A network-based examination of skull modularity in squamates via anatomical network analysis, focusing on the interplay between ‘microstomy’ (small-gaped feeding), fossoriality, and miniaturization in scolecophidians, reveals distinctive patterns of jaw connectivity across purported ‘ microstomatans’, supporting a more complex scenario of jaw evolution than traditionally portrayed.

A highly conserved ontogenetic limb allometry and its evolutionary significance in the adaptive radiation of Anolis lizards

The results demonstrate that the remarkable diversification of locomotor specialists in Anolis lizards are accessible through changes that are largely independent from ontogenetic growth trajectories, and therefore likely to be the result of modifications that manifest at the earliest stages of limb development.

Differing effects of size and lifestyle on bone structure in mammals

It is found that mammalian bone structure is highly disparate and it is shown that the investigated vertebral structure parameters mostly correlate with body size, but not lifestyle, while the opposite is true for humeral parameters.

First Report of Hemipenial Variation among Some Genera and Species of Shieldtail Snakes (Serpentes: Uropeltidae) from India and Sri Lanka

Gross hemipenial morphology can now serve to diagnose uropeltids to the genus level or species group, though more data and comparative series are needed to determine whether other characters, such as the number and location of spines, can potentially differentiate taxa at finer scales.

Lizards and snakes from the earliest Miocene of Saint-Gérand-le-Puy, France: an anatomical and histological approach of some of the oldest Neogene squamates from Europe

A taxonomical survey along with a histological/microanatomical approach on new squamate remains from the earliest Miocene of Saint-Gérand-le-Puy, France, an area that has been well known for its fossil discoveries since the nineteenth century.



Ecomorphological diversification in squamates from conserved pattern of cranial integration

It is demonstrated that highly diverse phenotypes, exemplified by lizards and snakes, can and do arise from differential selection acting on conserved patterns of phenotypic integration, and the primary drivers of their cranial evolution within a unified, quantitative framework.

Evolution of Cranial Shape in Caecilians (Amphibia: Gymnophiona)

A large-scale investigation into evolution of morphological variation in the skull of caecilian amphibians, a major clade of vertebrates, finds evidence of Morphological convergence in cranial shape, among species that have eyes covered by bone, resulting in a narrow bullet-shaped head.

Repeated evolution of limblessness and digging heads in worm lizards revealed by DNA from old bones

  • M. KearneyB. Stuart
  • Biology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2004
A phylogenetic analysis of two nuclear genes obtained from both fresh tissues and museum specimens of worm lizards shows the limbless Rhineuridae to be the most basal lineage, whereas the limbed Bipedidae occupy a more derived position as the sister–taxon to a Trogonophidae–Amphisbaenidae clade.

The ecological origins of snakes as revealed by skull evolution

An integrative geometric morphometric approach is used that suggests evolution from terrestrial to fossorial in the most recent common ancestor of extant snakes, and indicates that snakes later evolved novel craniofacial specializations through global acceleration of skull development.

Microanatomical diversity of amniote ribs: an exploratory quantitative study

A significant relationship was found between rib cortical thickness, global compactness, and lifestyle and the development of the spongiosa in the medullary region appears to be strongly correlated with size.

Microanatomy of the radius and lifestyle in amniotes (Vertebrata, Tetrapoda)

The discriminant function based on taxa of known lifestyle is used to infer the lifestyle of three extinct amniotes: the early nothosaur Pachypleurosaurus, therapsid Lystrosaurus and the synapsid Ophiacodon and these predictions are congruent with classical palaeoecological interpretations.

Eocene lizard from Germany reveals amphisbaenian origins

Morphometric analysis of body shape and ecology in squamates indicates that the postcranial anatomy of the new taxon is most consistent with opportunistically burrowing habits, which in combination with cranial reinforcement indicates that head-first burrowing evolved before body elongation and may have been a crucial first step in the evolution of amphisbaenian fossoriality.


This paper combines a molecular phylogeny for 27 species, morphometric data, and phylogenetic comparative methods to provide the first statistical phylogenetic tests of several long‐standing hypotheses for the evolution of snakelike body form, and finds no support for the hypothesized sequence going from body elongation to limb reduction to digit loss.

Skull osteology of the Eocene amphisbaenian Spathorhynchus fossorium (Reptilia, Squamata) suggests convergent evolution and reversals of fossorial adaptations in worm lizards

It is predicted that supposedly ‘unique’ cranial traits traditionally linked to fossoriality such as a fused orbitosphenoid and the reduction of the eye show a more complex character history than previously assumed, including both parallel evolution and reversals to superficially primitive conditions.

Head shape evolution in Gymnophthalmidae: does habitat use constrain the evolution of cranial design in fossorial lizards?

Results suggest that the evolution of head morphology in Gymnophthalmidae was shaped under the influence of microhabitat use rather than diet: burrowers have shorter heads with lower rostral angulation, independently of the prey consumed.