Palaeontology: A firm step from water to land

  title={Palaeontology: A firm step from water to land},
  author={Per Erik Ahlberg and Jennifer Alice Clack},
A project designed to discover fossils that illuminate the transition between fishes and land vertebrates has delivered the goods. At a stroke, our picture of that transition is greatly improved.When fins became limbsThe transition between fishes and limbed vertebrates, or tetrapods, occurred over 370 million years ago and required changes to virtually the entire body. Sensational fossil finds, and reinterpretations of old ones, have radically altered thinking on this topic in the past 20 years… 
Sarcopterygian Fishes, the “Lobe-Fins”
This chapter will introduce you to groups now known exclusively from fossils such as “dagger-toothed” onychodonts and porolepiforms named so for the special pores in their scales.
Fins, Fossils and Fingers
Three hundred and seventy-five million years ago, many different types of big fish lived in the sea. Gradually, some of them began approaching shallow water close to land. It became advantageous for
An autopodial-like pattern of Hox expression in the fins of a basal actinopterygian fish
Comparative analyses of Hox gene expression and regulation in teleost fish and tetrapods support the long-entrenched notion that the distal region of tetrapod limbs, containing the wrist, ankle and digits, is an evolutionary novelty and show that aspects of the development of the autopod are primitive to tetrapoids.
Sequences, stratigraphy and scenarios: what can we say about the fossil record of the earliest tetrapods?
The Polish trackways force a substantial reconsideration of the nature of the early tetrapod record when only body fossils are considered, and it is found that 95 per cent credible and confidence intervals for the origin of digit-bearing tetrapods extend into the Early Devonian and beyond.
Prey-Catching Behaviour in Mudskippers and Toads: A Comparative Analysis
It is shown that two extant vertebrate species, an amphibious fish and the common toad, which both feed on earthworms, have evolved the same modes of prey recognition.
The deep homology of the autopod: insights from hox gene regulation.
  • Marcus C. Davis
  • Environmental Science
    Integrative and comparative biology
  • 2013
Analysis of HoxA/D expression in a basal actinopterygian, the North American paddlefish, reveals patterns of expression long considered to be a unique developmental signature of the autopod and shown in tetrapods to be controlled by a "digit enhancer" regulatory landscape, which supports the notion that the autopid shares a deep homology with the distal endoskeleton of the fin of other gnathostomes.
A large onychodontiform (Osteichthyes: Sarcopterygii) apex predator from the Eifelian-aged Dundee Formation of Ontario, Canada
The Devonian marine strata of southwestern Ontario, Canada, have been well documented geologically, but their vertebrate fossils are poorly studied. Here we report a new onychodontiform
Hominin landscapes and co-evolutionary ecology : accommodating logical incoherence and complexity
Understanding primate (and human) evolutionary environments is a key goal of palaeoanthropology. The most recent contribution to this debate, the ‘tectonic landscape model’ (TLM) is the first to
Geology, Paleoclimatology and the Evolution of the Kidney: Some Explorations into the Legacy of Homer Smith
An overview of the relation between kidney development in different species and new developments in plate tectonics and paleoclimatology is performed, which likely had a remarkable effect on evolution.


Tetrapod-like middle ear architecture in a Devonian fish
It is shown that the spiracular region is radically transformed from osteolepiforms and represents the earliest stages in the origin of the tetrapod middle ear architecture, suggesting that the middle ear of early tetrapods evolved initially as part of a spiracular breathing apparatus.
The First Tetrapod Finds from the Devonian (Upper Famennian) of Latvia
The lower jaw of Ventastega is strikingly primitive in retaining fangs on the coronoid series, but shares many characters with those of other known Devonian tetrapods, and some of these features are interpreted as basal tetrapod synapomorphies.
The pelvic fin and girdle of Panderichthys and the origin of tetrapod locomotion
The evolution of tetrapod locomotion appears to have passed through a stage of body-flexion propulsion, in which the pelvic fins played a relatively minor anchoring part, before the emergence of hindlimb-powered propulsion in the interval between Panderichthys and Acanthostega.
Elginerpeton pancheni and the earliest tetrapod clade
Elginerpeton, described here on the basis of cranial remains from Scat Craig, is, together with the fragmentary genus Obruchevichthys from the Upper Frasnian of Latvia and Russia, the oldest known stem tetrapod.
The axial skeleton of the Devonian tetrapod Ichthyostega
A new reconstruction of Ichthyostega is shown based on extensive re-examination of original material and augmented by recently collected specimens and reveals hitherto unrecognized regionalization in the vertebral column.
Postcranial stem tetrapod remains from the Devonian of Scat Craig, Morayshire, Scotland
Overall, the postcranial bones combine apparent synapomorphies with Ichthyostega and characters which are uniquely primitive among stem-group tetrapods, which demonstrates that the typical stem tetrapod facial morphology had evolved before the end of the Frasnian.
The origin and early diversification of tetrapods
Devonian tetrapods were more fish-like than believed previously, whereas Lower Carboniferous tetrapod faunas contain early representatives of the amphibian and amniote lineages.
The Devonian tetrapod Acanthostega gunnari Jarvik: postcranial anatomy, basal tetrapod interrelationships and patterns of skeletal evolution
Comparison between axial skeletons of primitive tetrapods suggests that plesiomorphic fish-like morphologies were re-patterned in a cranio-caudal direction with the emergence of tetrapod vertebral regionalisation.
The pectoral fin of Tiktaalik roseae and the origin of the tetrapod limb
The pectoral appendage of a member of the sister group of tetrapods, Tiktaalik roseae, is described, which is morphologically and functionally transitional between a fin and a limb.
Geologic time scale 2004
An international team of over 40 stratigraphic experts, many actively involved in the International Commission of Stratigraphy (ICS), have helped to build the most up-to-date international