Faculty Opinions recommendation of A new Permian gnetalean cone as fossil evidence for supporting current molecular phylogeny.

2004 ◽  
Author(s):  
Guenter Theissen
Keyword(s):  
Molecular Phylogeny ◽  
Fossil Evidence

scholarly journals Possible poriferan body fossils in early Neoproterozoic microbial reefs

Nature ◽  
2021 ◽  
Author(s):  
Elizabeth C. Turner
Keyword(s):  
Molecular Phylogeny ◽  
Physical Characteristics ◽  
The Body ◽  
Physical Evidence ◽  
Microbial Carbonates ◽  
Fossil Evidence ◽  
Petrographic Feature ◽  
Body Fossil ◽  
Early Neoproterozoic ◽  
Neoproterozoic Era

AbstractMolecular phylogeny indicates that metazoans (animals) emerged early in the Neoproterozoic era1, but physical evidence is lacking. The search for animal fossils from the Proterozoic eon is hampered by uncertainty about what physical characteristics to expect. Sponges are the most basic known animal type2,3; it is possible that body fossils of hitherto-undiscovered Proterozoic metazoans might resemble aspect(s) of Phanerozoic fossil sponges. Vermiform microstructure4,5, a complex petrographic feature in Phanerozoic reefal and microbial carbonates, is now known to be the body fossil of nonspicular keratosan demosponges6–10. This Article presents petrographically identical vermiform microstructure from approximately 890-million-year-old reefs. The millimetric-to-centimetric vermiform-microstructured organism lived only on, in and immediately beside reefs built by calcifying cyanobacteria (photosynthesizers), and occupied microniches in which these calcimicrobes could not live. If vermiform microstructure is in fact the fossilized tissue of keratose sponges, the material described here would represent the oldest body-fossil evidence of animals known to date, and would provide the first physical evidence that animals emerged before the Neoproterozoic oxygenation event and survived through the glacial episodes of the Cryogenian period.

Molecular phylogeny and taxonomic evaluation of the genus Asaccus Dixon and Anderson, 1973 (Reptilia: Phyllodactylidae) in Iran

2020 ◽  
pp. 207-214
Author(s):  
Akbar Fattahi
Keyword(s):  
Molecular Phylogeny ◽  
Nuclear Gene ◽  
Genetic Distances ◽  
Genetic Lineage ◽  
New Taxon ◽  
Zagros Mountains ◽  
Relict Species ◽  
Taxonomical Revision ◽  
Two Populations ◽  
Taxonomic Evaluation

The Iranian species of the phyllodactylid geckos of the genus Asaccus are found only in the valleys of the Zagros Mountains, a region which represents an important area of endemism in western Iran. Recently, many relict species have been described from the central and southern parts of the Zagros Mountains, which were previously known as A. elisae. The recent descriptions of species within this complex suggest that diversity within the genus may be higher than expected and that its taxonomy and systematics should be revised. In the present study, phylogenetic relationships within the genus Asaccus were evaluated using two mitochondrial and one nuclear gene. Genetically, the genus shows high levels of variability. The molecular phylogeny of the genus suggests the presence of three main clades along the Zagros Mountains with the southern population (from the Hormozgan province) and one clade (A. sp8 and A. sp9) being sister taxon to A. montanus from UAE. The remaining samples are separated into two reciprocally monophyletic groups: the northern (Kurdistan, Kermanshah and Ilam provinces) and the central (Lorestan, Khuzestan, Kohgilouye-Bouyer Ahmad and Fars provinces) Zagros groups. The results of the present study suggest that populations attributed to A. elisae in Iran correspond to distinct lineages with high genetic distances. In brief, our results suggest that the genus needs a major taxonomical revision The Arabian origin of the genus has not been confirmed, because two populations from Zagros were located within the A. montanus, A. gallagheri and A. platyrhynchus clade. Further morphological analyses are needed to systematically define each genetic lineage as a new taxon.

Robert E. Grant's later views on organic development: the Swiney lectures on “Palaeozoology”, 1853–1857

1984 ◽  
Vol 11 (3) ◽  
pp. 395-413 ◽  
Author(s):  
ADRIAN DESMOND
Keyword(s):  
Steady State ◽  
Development Theory ◽  
Fossil Evidence

SUMMARY R. E. Grant's advocacy of transmutation is considered in relation to the scientific climate of the 1850s. To understand the palaeontological framework of his development theory, the unpublished “Palaeozoology” lectures, delivered in 1853–7, are analysed and his sources tabulated. The lectures are shown to contain the following additional themes: (1) a refutation of Lyell's steady-state geology, (2) support for serial development, (3) use of metamorphic effacement to explain the lack of pre-Silurian fossils, and (4) nebular hypothesis. The difficulty of supporting serial development using fossil evidence at this late date is discussed, and this difficulty is deemed to have contributed to the failure of Grant's theory of species “generation”.

Morphology, nomenclature and distribution of Bassia monticola (Chenopodiaceae-Amaranthaceae), a poorly known species from Western Asia

2020 ◽  
pp. 13-17
Author(s):  
A. P. Sukhorukov ◽  
M. A. Kushunina
Keyword(s):  
Molecular Phylogeny ◽  
Morphological Characters ◽  
Mountainous Regions ◽  
Western Asia

Kochia monticola was previously considered as a synonym for the widely distributed Irano-Turanian Panderia pilosa. After the merger of Kochia and Panderia with Bassia based on molecular phylogeny, K. monticola remained a synonym of Bassia pilosa. We claim that Bassia monticola, a name proposed by Kuntze (1891) for K. monticola, should be separated from B. pilosa based on morphological characters and localised distribution in mountainous regions of Iran, Iraq, Syria, and Lebanon at altitudes 1800–2600 m a. s. l.

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