A Silurian placoderm with osteichthyan-like marginal jaw bones
A three-dimensionally preserved 419-million-year-old placoderm fish from the Silurian of China is described that represents the first stem gnathostome with dermal marginal jaw bones (premaxilla, maxilla and dentary), features previously restricted to Osteichthyes.
Jaws and teeth of the earliest bony fishes
- H. Botella, H. Blom, Markus Dorka, P. Ahlberg, P. Janvier
- Environmental Science, GeographyNature
- 2 August 2007
Andreolepis and Lophosteus are not only the oldest but also the most phylogenetically basal securely identified osteichthyans known so far, indicating that they can be assigned to the stem group.
Ventastega curonica and the origin of tetrapod morphology
The skull, exceptionally preserved braincase, shoulder girdle and partial pelvis of Ventastega curonica are presented, a transitional intermediate form between the ‘elpistostegids’ Panderichthys and Tiktaalik and the Devonian tetrapods (limbed vertebrates) Acanthostega and Ichthyostega.
Silurian and earliest Devonian birkeniid anaspids from the Northern Hemisphere
The sculpture of scales and plates of articulated anaspids from the order Birkeniida is described and used to clarify the position of scale taxa previously left in open nomenclature, supporting a new anaspid taxonomy that includes both articulated and disarticulated material.
A NEW ACTINOPTERYGIAN FROM THE FAMENNIAN OF EAST GREENLAND AND THE INTERRELATIONSHIPS OF DEVONIAN RAY-FINNED FISHES
The scheme of relationships suggests that actinopterygians invaded freshwater environments at least four times during the Devonian, while age constraints indicate that many of the cladogenic events between ingroup taxa included in this study occurred during or before the Givetian.
Devonian vertebrates from East Greenland: a review of faunal composition and distribution
The Devonian vertebrate faunas of East Greenland are reviewed and their distribution discussed for the first time in the light of the most recently published stratigraphical framework for the area.…
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.
Vertebrate remains from Upper Silurian – Lower Devonian beds of Hall Land, North Greenland
- H. Blom
- Geology, Environmental Science
- 28 December 1999
Vertebrate microscopic remains of twenty-six taxa of thelodonts, heterostracans, osteostracans, anaspids, acanthodians and chondrichthyans are described from limestone beds in two localities of Late…
The sedimentary environment of the Late Devonian East Greenland tetrapods
Abstract The Late Devonian early tetrapods in East Greenland occur in the Celsius Bjerg Group. Key occurrences are located in a detailed stratigraphic section used here to interpret the sedimentary…
Phylogenetic relationships of the cyathaspidids (Heterostraci)
The present analysis investigates for the first time the phylogenetic relationships of the cyathaspidid heterostracans by the principle of global parsimony on the basis of 36 species and 1 outgroup taxon and shows a high degree of homoplasy.