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An investigation of the genus Mesacanthus (Chordata: Acanthodii) from the Orcadian Basin and Midland Valley areas of Northern and Central Scotland using traditional morphometrics.

Baron MG - PeerJ (2015)

Bottom Line: Based upon descriptions given during the 19th century, specimens of the genus Mesacanthus from the Orcadian Basin and Midland Valley areas of Northern and Central Scotland have historically been referred to a number of different species; of these, the most frequently discussed in the literature are M. mitchelli, M. peachi and M. pusillus.Based upon morphological and morphometric comparisons, this investigation has found that at least two species of Mesacanthus are valid (M. mitchelli and M. pusillus) as specimens from the Lower Devonian and Middle Devonian have been shown to differ significantly in a number of important ways.However, no evidence has been found for the validity of the second and distinct Middle Devonian species, M. peachi.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Earth Science, University of Cambridge , Cambridge , United Kingdom.

ABSTRACT
Mesacanthus is a common and speciose genus of acanthodian fish from Lower Old Red Sandstone and Middle Old Red Sandstone assemblages (representing the Lower Devonian and Middle Devonian respectively) and is well represented in many palaeoichthyology collections in the UK. Based upon descriptions given during the 19th century, specimens of the genus Mesacanthus from the Orcadian Basin and Midland Valley areas of Northern and Central Scotland have historically been referred to a number of different species; of these, the most frequently discussed in the literature are M. mitchelli, M. peachi and M. pusillus. In order to test the validity of these three species, traditional morphometric analyses were carried out on over 100 specimens of Mesacanthus, from both the Lower Devonian and the Middle Devonian, that cover the full range of known localities for these taxa in Northern and Central Scotland. Based upon morphological and morphometric comparisons, this investigation has found that at least two species of Mesacanthus are valid (M. mitchelli and M. pusillus) as specimens from the Lower Devonian and Middle Devonian have been shown to differ significantly in a number of important ways. However, no evidence has been found for the validity of the second and distinct Middle Devonian species, M. peachi.

No MeSH data available.


Related in: MedlinePlus

Preservational differences between localities that have produced specimens of Mesacanthus peachi.Specimens of M. peachi from Tynet Burn (A) and Achanarras (B) showing the differences in preservation between the areas. Both specimens show a high degree of post mortem damage (folding and twisting) and so neither was suitable for use in this study. Scale bar = 20 mm.
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fig-8: Preservational differences between localities that have produced specimens of Mesacanthus peachi.Specimens of M. peachi from Tynet Burn (A) and Achanarras (B) showing the differences in preservation between the areas. Both specimens show a high degree of post mortem damage (folding and twisting) and so neither was suitable for use in this study. Scale bar = 20 mm.

Mentions: In all of the analyses, the holotype of M. mitchelli (NHMUK PV P560) plotted well within the standard range for the species; it did not plot close to specimens of M. peachi and M. pusillus (see Figs. 2, 3A–3D, 4 and 8).


An investigation of the genus Mesacanthus (Chordata: Acanthodii) from the Orcadian Basin and Midland Valley areas of Northern and Central Scotland using traditional morphometrics.

Baron MG - PeerJ (2015)

Preservational differences between localities that have produced specimens of Mesacanthus peachi.Specimens of M. peachi from Tynet Burn (A) and Achanarras (B) showing the differences in preservation between the areas. Both specimens show a high degree of post mortem damage (folding and twisting) and so neither was suitable for use in this study. Scale bar = 20 mm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4631467&req=5

fig-8: Preservational differences between localities that have produced specimens of Mesacanthus peachi.Specimens of M. peachi from Tynet Burn (A) and Achanarras (B) showing the differences in preservation between the areas. Both specimens show a high degree of post mortem damage (folding and twisting) and so neither was suitable for use in this study. Scale bar = 20 mm.
Mentions: In all of the analyses, the holotype of M. mitchelli (NHMUK PV P560) plotted well within the standard range for the species; it did not plot close to specimens of M. peachi and M. pusillus (see Figs. 2, 3A–3D, 4 and 8).

Bottom Line: Based upon descriptions given during the 19th century, specimens of the genus Mesacanthus from the Orcadian Basin and Midland Valley areas of Northern and Central Scotland have historically been referred to a number of different species; of these, the most frequently discussed in the literature are M. mitchelli, M. peachi and M. pusillus.Based upon morphological and morphometric comparisons, this investigation has found that at least two species of Mesacanthus are valid (M. mitchelli and M. pusillus) as specimens from the Lower Devonian and Middle Devonian have been shown to differ significantly in a number of important ways.However, no evidence has been found for the validity of the second and distinct Middle Devonian species, M. peachi.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Earth Science, University of Cambridge , Cambridge , United Kingdom.

ABSTRACT
Mesacanthus is a common and speciose genus of acanthodian fish from Lower Old Red Sandstone and Middle Old Red Sandstone assemblages (representing the Lower Devonian and Middle Devonian respectively) and is well represented in many palaeoichthyology collections in the UK. Based upon descriptions given during the 19th century, specimens of the genus Mesacanthus from the Orcadian Basin and Midland Valley areas of Northern and Central Scotland have historically been referred to a number of different species; of these, the most frequently discussed in the literature are M. mitchelli, M. peachi and M. pusillus. In order to test the validity of these three species, traditional morphometric analyses were carried out on over 100 specimens of Mesacanthus, from both the Lower Devonian and the Middle Devonian, that cover the full range of known localities for these taxa in Northern and Central Scotland. Based upon morphological and morphometric comparisons, this investigation has found that at least two species of Mesacanthus are valid (M. mitchelli and M. pusillus) as specimens from the Lower Devonian and Middle Devonian have been shown to differ significantly in a number of important ways. However, no evidence has been found for the validity of the second and distinct Middle Devonian species, M. peachi.

No MeSH data available.


Related in: MedlinePlus