Live birth in the Devonian period

  title={Live birth in the Devonian period},
  author={John A. Long and Kate Trinajstic and Gavin Young and Timothy John Senden},
The extinct placoderm fishes were the dominant group of vertebrates throughout the Middle Palaeozoic era, yet controversy about their relationships within the gnathostomes (jawed vertebrates) is partly due to different interpretations of their reproductive biology. Here we document the oldest record of a live-bearing vertebrate in a new ptyctodontid placoderm, Materpiscis attenboroughi gen. et sp. nov., from the Late Devonian Gogo Formation of Australia (approximately 380 million years ago… 

Placodermi (Armoured Fishes)

They are the earliest true jawed vertebrates that show a number of anatomical features, illustrating the primitive condition in forthcoming other vertebrates and are the first fish to adapt to different modes of life and to various reproductive strategies.

Devonian arthrodire embryos and the origin of internal fertilization in vertebrates

It is shown that Incisoscutum and some phyllolepid arthrodires possessed pelvic girdles with long basipterygia that articulated distally with an additional cartilaginous element or series, as in chondrichthyans, indicating that the pelvic fin was used in copulation.

Placoderms (Armored Fish): Dominant Vertebrates of the Devonian Period

Placoderms, the most diverse group of Devonian fishes, were globally distributed in all habitable freshwater and marine environments, like teleost fishes in the modern fauna, and recent claims that they form a paraphyletic group are based on highly derived Late Devonian forms.

Superfoetative viviparity in a Carboniferous chondrichthyan and reproduction in early gnathostomes

The fossilized remains of two specimens of Harpagofututor volsellorhinus from the Upper Mississippian of Montana now provide the first direct evidence of matrotrophic live birth in a Palaeozoic chondrichthyan and of superfoetation in an extinct fish.

A preliminary note of egg-case oviparity in a Devonian placoderm fish

Six enigmatic fossils from the Famennian (Devonian) Cleveland Shale in Ohio, U.S.A., are interpreted here as arthrodiran (Placodermi) egg cases, representing the first record for a non-chondrichthyan producer and suggesting external fertilization as the primitive gnathostome reproductive mode.

Re‐evaluation of the ontogeny and reproductive biology of the Triassic fish Saurichthys (Actinopterygii, Saurichthyidae)

New data on the reproductive biology of these species is presented, giving unprecedented insights into their life‐history, including Ossified squamation and gradual allometric growth suggests that neonates did not undergo metamorphosis and were relatively precocial.

New Morphological Information on the Ptyctodontid Fishes (Placodermi, Ptyctodontida) from Western Australia

ABSTRACT A full description of a complete and articulated, three-dimensionally preserved, placoderm fish, Materpiscis attenboroughi (Ptyctodontida), from the Late Devonian Gogo Formation is

The characters of Palaeozoic jawed vertebrates

A clearly stated hierarchy of synapomorphies covering the jaw-bearing stem gnathostomes and osteichthyan and chondrichthyan stem groups is provided and a proposed synapomorphy scheme is used to evaluate the status of the problematic fossil groups Acanthodii and Placodermi.

Terrestrial Origin of Viviparity in Mesozoic Marine Reptiles Indicated by Early Triassic Embryonic Fossils

The new specimen contains the oldest fossil embryos of Mesozoic marine reptile that are about 10 million years older than previous such records and strongly indicates a terrestrial origin of viviparity, in contrast to the traditional view.

Exceptional preservation of organs in Devonian placoderms from the Gogo lagerstätte.

Arthrodires show the earliest phylogenetic evidence for repositioning of the gnathostome heart associated with the evolution of the complex neck region in jawed vertebrates.



Live birth in Cretaceous marine lizards (mosasauroids)

  • M. CaldwellM. S. Lee
  • Environmental Science, Geography
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2001
Viviparity in early medium-sized amphibious aigialosaurs may have freed them from the need to return to land to deposit eggs, and permitted the subsequent evolution of gigantic totally marine mosasaurs.

Ptyctodontid fishes (Vertebrata, Placodermi) from the Late Devonian Gogo Formation, Western Australia, with a revision of the European genus Ctenurella Ørvig, 1960

A new reconstruction of the head shield of Ctenurella gladbachensis Orvig, 1960 from Bergisch-Gladbach permits this taxon to be generically defined from the Gogo species previously referred to that genus.

Exceptional preservation of nerve and muscle tissues in Late Devonian placoderm fish and their evolutionary implications

The oldest soft tissue discovered in gnathostomes is described, which includes striated muscle fibres, circulatory and nerve tissues, preserved as phosphatized structures precipitated by microbial infilling of small, protected areas under the headshield of the arthrodire, Eastmanosteus calliaspis.

First record of live birth in Cretaceous ichthyosaurs: closing an 80 million year gap

  • E. MaxwellM. Caldwell
  • Environmental Science, Geography
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 2003
New fossils of embryonic ichthyosaurs are both the geologically youngest and the physically smallest known ichysosaur embryos, and are located within the body cavity of an adult, presumably the mother.

The unique fossil assemblage from the Lode Quarry (Upper Devonian, Latvia)

Abstract. The unique fossil fauna from the Lode clay quarry, lower Frasnian, Latvia, includes a diverse ichthyofauna of at least 15 taxa of agnathans and gnathostomes, representing most of the major

Maximization of evolutionary trends for placental viviparity in the spadenose shark, Scoliodon laticaudus

Comparisons with other species of placental and non-placental sharks show that S. laticaudus has a highly advanced form of matrotrophy, and maternal nutrients appear to be acquired by placental transport and by imbibition of uterine fluid.

Observations on the ptyctodont fish, Rhamphodopsis Watson

The occurrence of strong sexual dimorphism in the pelvic region is confirmed, and descriptions are given of the ‘claspers' in males, and of the large scale-bearing pelvic fins and their endoskeleton in females.


“Recent Advances in the Origin and Early Radiation of Vertebrates” honors Dr. Hans-Peter Schultze for his influential body of work on lower vertebrates spanning the past 40 years, and counting. The

The relationship of placoderms

ABSTRACT A review of the evidence suggests that placoderms are more closely related to osteichthyans than chondrichthyans. A new phylogeny of placoderms is proposed in which the ptyctodonts are

An x-ray tomography facility for quantitative prediction of mechanical and transport properties in geological, biological, and synthetic systems

A fully integrated X-ray tomography facility with the ability to generate tomograms with 20483 voxels at 2 micron spatial resolution was built to satisfy the requirements of a virtual materials