An early tetrapod from ‘Romer's Gap’

  title={An early tetrapod from ‘Romer's Gap’},
  author={Jennifer Alice Clack},
  • J. Clack
  • Published 4 July 2002
  • Geography
  • Nature
The fossil record of early tetrapods has been increased recently by new finds from the Devonian period and mid–late Early Carboniferous period. [] Key Result The new taxon includes a pes with five robust digits, but a very small, possibly supernumerary digit preserved on the manus suggests the presence of polydactyly. Polydactylous early tetrapods may have survived beyond the end of the Devonian and pentadactyly cannot be assumed for the pes. However, the pes has characteristics that distinguish it from the…

Earliest Carboniferous tetrapod and arthropod faunas from Scotland populate Romer's Gap

It is concluded that the gap in the fossil record has been an artifact of collection failure and a series of discoveries of Tournaisian-age localities in Scotland that have yielded a wealth of new tetrapod and arthropod fossils.

A partial lower jaw of a tetrapod from “Romer's Gap”

ABSTRACT The first half of the Mississippian or Early Carboniferous (Tournaisian to mid- Viséan), an interval of about 20 million years, has become known as “Romer's Gap” because of its poor tetrapod

Baraminological analysis of Devonian and Carboniferous tetrapodomorphs

According to evolutionary theory, the origin of tetrapods (or limbed vertebrates) from a fish-like ancestor during the Devonian Period was one of the major events in the history of life. Devonian

A uniquely specialized ear in a very early tetrapod

Ichthyostega's braincase and ear region defied interpretation, such that conventional anatomical terms seemed inapplicable, and can now be seen to form part of a highly specialized ear, probably a hearing device for use in water.


The Scat Craig assemblage not only represents the earliest known remains of tetrapodomorphs with limbs rather than paired fins but is actually one of the largest suites of Tetrapod material from the Devonian.

A fish and tetrapod fauna from Romer's Gap preserved in Scottish Tournaisian floodplain deposits

The end‐Devonian mass extinction has been framed as a turning point in vertebrate evolution, enabling the radiation of tetrapods, chondrichthyans and actinopterygians. Until very recently ‘Romer's

Devonian climate change, breathing, and the origin of the tetrapod stem group.

  • J. Clack
  • Environmental Science, Geography
    Integrative and comparative biology
  • 2007
The diversification of the tetrapod stem group occurred during the late Middle through the Late Devonian, that is from the Givetian to Famennian stages about 385-365 million years ago, and plant diversification was at its most rapid, changing the character of the landscape and contributing, via soils, soluble nutrients, and decaying plant matter, to anoxia in all water systems.

Pederpes finneyae, an articulated tetrapod from the tournaisian of Western Scotland

The postcranial skeleton of Pederpes shows several unique features, including the structure of the leading edges of the cleithrum and clavicle, the form of the rib flanges and a possible supernumerary digit on the manus.

Gaining Ground: The Origin and Evolution of Tetrapods

Gaining Ground brings together Jennifer Clack's work of the past two decades on Paleozoic tetrapod evolution, with particular focus on her specialty—the earliest known tetrapods of the Late Devonian.



An amniote-like skeleton from the Early Carboniferous of Scotland

A small, highly ossified, postcranial skeleton of a terrestrially adapted, amniote-like tetrapod from the Mid Viséan is reported, which shows the earliest known pentadactyl manus and pushes back the known occurrence of terrestrial vertebrates closer to the origin of tetrapods.

A new Early Carboniferous tetrapod with a mélange of crown-group characters

  • J. Clack
  • Biology, Environmental Science
  • 1998
A new taxon is described from this locality that not only combines characters of each lineage, but also represents the basal member of a third Palaeozoic group, the baphetids.

Polydactyly in the earliest known tetrapod limbs

The morphology of the specimens suggests that limbs with digits may have been adaptations to an aquatic rather than a terrestrial environment, and challenges pentadactyly as primitive for tetrapods.

The postcranial skeleton of the Devonian tetrapod Tulerpeton curtum Lebedev

A cladistic analysis indicates that Tulerpeton is a reptiliomorph stem-group amniote and the earliest known crown-group tetrapod: Acanthostega and Ichthyostega are successively more derived plesion stem- group tetrapods and do not consititute a monophyletic ichthyostegalian radiation.

Earliest known tetrapod braincase and the evolution of the stapes and fenestra ovalis

ACANTHOSTEGA gunnari, from the Upper Devonian (Famennian) of East Greenland, is the most primitive known tetrapod, and retains many fish-like characters1–4. I report here the discovery of further

The Carboniferous Amphibian Proterogyrinus scheelei Romer, and the Early Evolution of Tetrapods

Proterogyrinus scheelei Romer, from the Upper Mississippian of Greer, West Virginia, is one of the earliest known members of the amphibian infraorder Embolomeri, and has no undisputed synapomorphies with reptiles either, making it impossible to support close relationship between the two groups.

On the Amphibian Crassigyrinus scoticus Watson from the Carboniferous of Scotland

A case is made for the 'sister-group' relation of Crassigyrinus to the anthracosauroids and a cladogram presented of the subgroups involved; it is, however, difficult to make a case for the close relationship of CrASSIGyrinus and the Seymouriamorpha and the closeness of relationship of the latter to anthracosaurs is questioned.

The phylogenetic trunk: maximal inclusion of taxa with missing data in an analysis of the lepospondyli (Vertebrata, Tetrapoda).

The phylogenetic trunk approach is proposed to allow optimization of taxonomic inclusion and tree stability and finds a single most-parsimonious tree, or trunk, after the removal of one taxon identified as being problematic.

Amniote origins : completing the transition to land

This paper presents an integrated approach to the Origin of Amniotes: Completing the Transition to Land using Squared Change Parsimony at the Amniote Transition and presents a new perspective in Tetrapod Phylogeny.