Development of teeth and jaws in the earliest jawed vertebrates

  title={Development of teeth and jaws in the earliest jawed vertebrates},
  author={Martin R{\"u}cklin and Philip C. J. Donoghue and Zerina Johanson and Kate Trinajstic and Federica Marone and Marco Stampanoni},
Teeth and jaws constitute a model of the evolutionary developmental biology concept of modularity and they have been considered the key innovations underpinning a classic example of adaptive radiation. However, their evolutionary origins are much debated. Placoderms comprise an extinct sister clade or grade to the clade containing chondrichthyans and osteichthyans, and although they clearly possess jaws, previous studies have suggested that they lack teeth, that they possess convergently… 

Romundina and the evolutionary origin of teeth

‘supragnathal’ toothplates from the acanthothoracid placoderm Romundina stellina comprise multi-cuspid teeth, each composed of an enameloid cap and core of dentine, which suggests that it has been lost in other placoderms.

Tooth replacement in early sarcopterygians

A more complex evolutionary history of tooth replacement is suggested in the Devonian sarcopterygian fishes Onychodus, Eusthenopteron and Tiktaalik and the living coelacanth Latimeria based on microfocus- and synchrotron radiation-based X-ray microtomography.

Evolutionary origins of teeth in jawed vertebrates: conflicting data from acanthothoracid dental plates (‘Placodermi’)

Substantial differences are demonstrated between the articulated and unquestionable acanthothoracid dental plates, disputing the identity of the isolated plate of R. stellina as a dental plate, and thus its relevance to questions of tooth evolution.

Marginal dentition and multiple dermal jawbones as the ancestral condition of jawed vertebrates

This work used synchrotron microtomography to describe the fossil dentitions of so-called acanthothoracids, the most phylogenetically basal jawed vertebrates with teeth, belonging to the genera Radotina, Kosoraspis, and Tlamaspis (from the Early Devonian of the Czech Republic), and proposes these characteristics as ancestral for all jawing vertebrates.

A Silurian maxillate placoderm illuminates jaw evolution

A second Silurian maxillate placoderm is described that more securely bridges the jawless toothlike plates of placoderms to the development of the jawed condition that ultimately led to the three-boned jaw in ancestors of modern vertebrates.

The ins and outs of the evolutionary origin of teeth

It has been shown that teeth develop from dermal, endodermal or mixed epithelia and, therefore, developmental distinctions between teeth and dermal denticles are diminished, and the “inside‐out” hypothesis must be rejected.

A 26408 : Evolutionary origin of teeth

The available evidence supports an origin of teeth through extension of odontogenic competence from the external dermis to the oropharynx.

The origin of conodonts and of vertebrate mineralized skeletons

The hypothesis that teeth evolved before jaws and the inside-out hypothesis of dental evolution must be rejected; teeth seem to have evolved through the extension of odontogenic competence from the external dermis to internal epithelium soon after the origin of jaws.

The stem osteichthyan Andreolepis and the origin of tooth replacement

A three-dimensional virtual dissection of the dentition of a 424-million-year-old stem osteichthyan, Andreolepis hedei, is reported, using propagation phase-contrast synchrotron microtomography, with a reconstruction of its growth history.



Teeth before jaws? Comparative analysis of the structure and development of the external and internal scales in the extinct jawless vertebrate Loganellia scotica

A test of the phylogenetic distribution of oral and pharyngeal scales and teeth in vertebrates indicates that odontodes are first expressed in an external position, suggesting that internal odontode evolved through the expansion of odontogenic competence from external to internal epithelia.

Placoderm fishes, pharyngeal denticles, and the vertebrate dentition

Placodermi would seem to provide little evidence for the early evolution of dentitions, or of denticle whorls, or tooth families, at the base of the clade of jawed fishes, however, organized denticles do occur at the rear of the placoderm gill chamber, but are associated with the postbranchial lamina of the anterior trunkshield, assumed to be part of the dermal cover.

The odontode explosion: The origin of tooth‐like structures in vertebrates

It is shown how teeth can form equally from any epithelium, be it endoderm, ectoderm or a combination of the two and that the gene expression programs of oral versus pharyngeal teeth are remarkably similar.

Dual epithelial origin of vertebrate oral teeth

A dominant role for the neural crest mesenchyme over epithelia in tooth initiation is suggested and an essential factor in teeth evolution was the odontogenic capacity of neural crest cells, regardless of possible ‘outside-in’ or ‘inside-out’ influx of the epithelium.

First tooth-set outside the jaws in a vertebrate

It is demonstrated that holocephalan toothplate ontogeny differs fundamentally from all other extant gnathostome examples, and how the conjunction of these teeth and toothplates challenges the monophyly of an extinct chondrichthyan clade, the Petalodontiformes.

Skeletal histology of Bothriolepis canadensis (Placodermi, Antiarchi) and evolution of the skeleton at the origin of jawed vertebrates

The results of this work support the interpretation that the external skeleton of Bothriolepis canadensis is comprised exclusively of cellular dermal bone tissue, and highlight the importance of anatomical and ontogenetic context in the interpretation of fossil tissues.

Developmental and evolutionary origins of the vertebrate dentition: molecular controls for spatio-temporal organisation of tooth sites in osteichthyans.

The rainbow trout (Oncorhynchus mykiss) as a developmental model surpasses both zebrafish and mouse for a more widespread distribution of teeth in the oro-pharynx as the basis for general vertebrate

The braincase and jaws of a Devonian ‘acanthodian’ and modern gnathostome origins

The first-known braincase of an Early Devonian acanthodian is presented, andylogenetic analysis resolves Ptomacanthus as either the most basal chondrichthyan or as the sister group of all living gnathostomes, to provide a more detailed picture of the acquisition of early Gnathostome characters.

Origin and evolution of gnathostome dentitions: a question of teeth and pharyngeal denticles in placoderms

The fossil group Placodermi is the most phylogenetically basal of the clade of jawed vertebrates but lacks a marginal dentition comparable to that of the dentate Chondrichthyes, Acanthodii and

The pattern of histogenesis and growth of tooth plates in larval stages of extant lungfish.

Comparison of new data obtained in this study on Protopterus aethiopicus and Neoceratodus forsteri has confirmed the suggestion that the pattern of histogenesis of tooth plates in the early larval stages is very similar in the two genera.