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Designed for palaeontology courses in biology and geology departments, this leading text will also be of interest to enthusiasts who want to experience the flavour of how the research is done. The book is strongly phylogenetic, and this makes it a source of current data on vertebrate evolution. Study aids include key questions, research to be done and recommendations of further reading and websites.
Zoologica Scripta, 2008
Phylogenetic relationships within the Arvicolinae are examined based on two genes (mitochondrial cytb, nuclear GHR exon 10) and 296 morphological, developmental, behavioural, ecological and cytogenetic characters. To inspect the phylogenetic ‘behaviour’ of individual taxa, basic maximum-parsimony and Bayesian phylogenetic analyses were accompanied by experiments based on different data-partition combinations, ‘slow–fast’ character weighting, and inclusion/exclusion of individual problematic taxa. Ellobius, Prometheomys and Lagurus are the most basal arvicolines; Dicrostonyx, Phenacomys and Arborimus form a clade (Dicrostonychini s.lat.); the ‘core arvicolines’ include three subclades: Lemmini (Synaptomys, Lemmus, Myopus), Clethrionomyini (Eothenomys, Myodes) and Arvicolini (Arvicola, Chionomys, Stenocranius and Microtus, the last with six monophyletic subgenera: Alexandromys, ‘Neodon’, Mynomes, Lasiopodomys, Terricola, and Microtus s.str.). Position of Ondatra and Dinaromys is uncertain, probably compromised by highly homoplastic morphological characters.
1984
Cricetops, an extinct cricetid from the mid-Oligocene of Mongolia and Kazakhstan, and Lophiomys, a peculiar cricetid living in eastern Africa, share dorsoventral expansion ofthe jugal bone and enclosure of fossettids in the transverse crests of M1. They are proposed as each other's closest relative and included in the subfamily Lophiomyinae. Emphasis on transverse wear is shared by these genera and the living Cricetinae: Cricetulus, Phodopus, Mesocricetus, and Cricetus. The two subfamilies are considered closest relatives and placed in the muroid family Cricetidae. Cricetops and the living cricetines are chiefly northern Asiatic groups. Immigration to Africa from Asia is proposed for the ancestors of Lophiomys.
Phylogenetic analyses were conducted on cytochrome b sequence data of the most geographically and taxonomically broad sampling of Cavia taxa to date. Primary objectives included providing the first extensive molecular phylogenetic framework for the genus, testing the taxonomic and systematic hypotheses of previous authors and providing insight into the evolutionary and biogeographic history of the genus. Support was found for the morphologically defined species C. aperea, C. tschudii, C. magna and C. fulgida and the taxonomic placement of taxa previously subject to conflicting taxonomic opinions (e.g. C. nana, C. anolaimae and C. guianae) was further resolved. Additionally, we elevate the Ecuadorian C. a. patzelti to species status, restrict the distributional limits and suggest taxonomic affiliations of some C. tschudii subspecies, and provide strong evidence for the geographic origin of guinea pig domestication. Finally, we provide an estimated evolutionary timeline for the genus Cavia, which appears to extend well into the late Miocene.
Molecular Biology, 2009
Phylogenetic analysis of the supraspecies relationships was carried out using partial sequences of two nuclear genes in the subfamily Arvicolinae, which is one of the youngest and species-rich groups of myomorph rodents. The analysis with the new data resolved the majority of polytomy nodes in the phylogenetic trees reported for Arvicolinae, suggesting a gradual, rather than a saltatory, mode for their evolution. Mole voles Ellobiusini, steppe voles Lagurini, and gray voles Arvicolini were fount to be a monophyletic group that corresponds to the latest third wave of radiation within the subfamily. Red-back voles Myodini (=Clethrionomini) are a sister clade to this group and correspond to the second radiation wave. The order of divergence remained unresolved for the earliest radiation wave (Ondatrini, Prometheomyini, Dicrostonychini, and Lemmini). The close relationships observed for mole, gray, and steppe voles are unexpected and contradict the conventional views that Ellobiusini are an ancient group and are separate from all other voles on evidence of the extreme simplicity of their rooted molars and the peculiar structure of their skull and postcranial skeleton. It was assumed that many of these morphological characters indicate adaptation to subterranean life and provide no phylogenetic signal.
Comptes Rendus Palevol, 2011
Proceedings of the National Academy of Sciences, 2009
The early evolutionary and paleobiogeographic history of the diverse rodent clade Hystricognathi, which contains Hystricidae (Old World porcupines), Caviomorpha (the endemic South American rodents), and African Phiomorpha (cane rats, dassie rats, and blesmols) is of great interest to students of mammalian evolution, but remains poorly understood because of a poor early fossil record. Here we describe the oldest well-dated hystricognathous rodents from an earliest late Eocene (Ϸ37 Ma) fossil locality in the Fayum Depression of northern Egypt. These taxa exhibit a combination of primitive and derived features, the former shared with Asian ''baluchimyine'' rodents, and the latter shared with Oligocene phiomorphs and caviomorphs. Phylogenetic analysis incorporating morphological, temporal, geographic, and molecular information places the new taxa as successive sister groups of crown Hystricognathi, and supports an Asian origin for stem Hystricognathi and an Afro-Arabian origin for crown Hystricognathi, stem Hystricidae, and stem Caviomorpha. Molecular dating of early divergences within Hystricognathi, using a Bayesian ''relaxed clock'' approach and multiple fossil calibrations, suggests that the split between Hystricidae and the phiomorphcaviomorph clade occurred Ϸ39 Ma, and that phiomorphs and caviomorphs diverged Ϸ36 Ma. These results are remarkably congruent with our phylogenetic results and the fossil record of hystricognathous rodent evolution in Afro-Arabia and South America.
Molecular Biology and Evolution, 2002
A molecular phylogeny of the rodent superfamily Cavioidea was derived using two nuclear sequences (exon #10 of the growth hormone receptor gene and intron #1 of the transthyretin gene) and one mitochondrial gene (12S rRNA). A combined analysis produced a highly derived and well-supported phylogenetic hypothesis that differed from traditional taxonomy primarily in the placement of two taxa. Kerodon, traditionally included within the subfamily Caviinae with guinea pigs and its relatives, is placed sister to the family Hydrochaeridae and closely aligned with the subfamily Dolichotinae. Inclusion of Hydrochaeris within the Caviidae renders the familial classification paraphyletic. Our data further support the taxonomic separation of the families Agoutidae and Dasyproctidae. Both the molecular and traditional morphological interpretations are assessed in testing an ecological constraints hypothesis regarding social behaviors. Whereas traditional taxonomy is consistent with an environmental constraints explanation for social behavior, the molecular data suggest that phylogenetic effects may be a more important factor in the evolution of social behavior in this group. Although lineage-specific rate heterogeneity was identified in all three molecular data sets, no significant support was obtained for the metabolic rate hypothesis. However, both nuclear genes displayed patterns in accordance with the generation time hypothesis.
Evolution of hypsodonty in a cricetid (Rodentia) lineage: preliminary results using patch analysis. En: Moreno-Azanza, M., Díaz-Martínez, I., Gasca, J.M., Melero-Rubio, M., Rabal-Garcés, R. y Sauqué, V. (coords). Cidaris, número 30, VIII Encuentro de Jóvenes Investigadores en Paleontología, volumen de actas, 247-251.
2011
In response to environmental changes in the Northern hemisphere, several lines of brachyodont-bunodont cricetid rodents evolved during the Late Miocene as “microtoid cricetids.” Major evolutionary trends include increase in the height of cheek tooth crowns and development of prismatic molars. Derived from a possible Megacricetodon or Democricetodon ancestry, highly specialised microtoid cricetids first appeared with Microtocricetus in the Early Vallesian (MN 9) of Eurasia. Because of the morphological diversity and degree of parallelism, phylogenetic relationships are difficult to detect. The Trilophomyinae, a more aberrant cricetid side branch, apparently became extinct without descendants. Two branches of microtoid cricetids can be recognized that evolved into “true” arvicolids: (1) Pannonicola (= Ischymomys) from the Late Vallesian (MN 10) to Middle Turolian (MN 12) of Eurasia most probably gave rise to the ondatrine lineage (Dolomys and Propliomys) and possibly to Dicrostonyx, w...
2013
1100-1120 Exploring the patterns of cranial and mandibular co-variation within the order Rodentia.
The genus Cricetodon was erected by Lartet, 1851, to designate hamster-like rodents from the Miocene locality Sansan (Gers), France. Lartet distinguished three species with the following diagnoses : C. sansaniense: Un peu plus grand que le Hamster; C. medium: D'un tiers moindre que le Cricetodon sansaniense et plus petit que notre rat noir; C. minus: Plus petit que notre souris domestique. Schaub, 1925, in his revision of the genus, chose C. sansaniense as the typespecies. Fahlbusch, 1964 chose a lectotype for C. sansaniense from a small Sansan collection kept in the Museum &Histoire Naturelle in Paris; this collection may have been collected by Lartet himself.
1995
Introduction 1 Evolutionary Relationships within Sigmodontinae 2 Taxonomic History of the Phyllotines ...
Molecular Phylogenetics and Evolution, 2006
Journal of Mammalogy, 2021
The Reithrodontomys tenuirostris species group is considered “the most specialized” within the genus Reithrodontomys from morphological and ecological perspectives. Previous studies based on molecular data recommended changes in the taxonomy of the group. In particular, R. microdon has been the most taxonomically questioned, with the suggestion that it constitutes a complex of cryptic species. We analyzed the phylogenetic relationships of the R. tenuirostris species group using DNA sequences from the mitochondrial Cytochrome b gene and Intron 7 of the nuclear beta fibrinogen gene. In addition, divergence times were estimated, and possible new taxa delimited with three widely used species delimitation methods. Finally, possible connectivity routes based on shared haplotypes were tested among the R. microdon populations. All species were recovered as monophyletic with the exception of R. microdon, whose individuals were grouped into four different haplogroups, one of which included sp...
Journal of Paleontology, 2016
The genus Neocricetodon represents one of the most diverse radiations of extinct cricetines. Its early evolution remains unclear, mainly owing to the incomplete fossil record. One of the earliest and least known species of this genus is N. moldavicus described from the early late Miocene localities Bujor 1 and Calfa, Moldova. We reexamined the type material of this species and compared it with other species of Neocricetodon. Despite its old geological age, N. moldavicus demonstrates rather advanced dental morphology including the anterocone of M1 being deeply split; mesolophs and mesolophids partially reduced; and the labial spur of the anterolophule, ectomesolophids, and lingual anterolophid of m2 lacking. The phylogenetic analysis of 15 Neocricetodon species based on 22 dental characters revealed three synapomorphies for the genus: presence of the M1 labial anterolophule, the four-rooted M2, and presence of the labial anterolophulid of m1. “Kowalskia cf. schaubi” from Rudabánya an...
Zoological Journal of the Linnean Society, 2004
Major crown-groups of rodents were well established in the early Tertiary, and fossils provide an invaluable window into their evolutionary history. The main focus of this project was to perform a cladistic assessment of the dental evidence for early Tertiary rodent cladogenesis-the masticatory apparatus and teeth are the most frequently preserved anatomical features in the fossil record. We focused on groups that existed in a period corresponding to their early history, combining fossils belonging to extinct lineages and to stem-groups leading to modern lineages. While the monophyly of some groups is not systematically explored, our results have important implications for high-level rodent relationships and systematics. These results are consistent with those of recent molecular phylogenies and reliably congruent with the stratigraphic record, thus enhancing the pertinence of dental characters for phylogenetic inference. Our approach provides evidence of a fundamental dichotomy in early rodent history. Two major clades have been identified: (1) the earliest 'ctenodactyloid' (Ctenodactylidae, Chapattimyidae, Yuomyidae, Diatomyidae) and hystricognathous (Tsaganomyidae, Baluchimyinae, 'phiomorphs', 'caviomorphs') rodents, and (2) the earliest 'ischyromyoid' rodents with their closest relatives (Muroidea + Dipodoidea + Geomyoidea + Anomaluroidea + Castoroidea + Sciuravidae + Gliroidea, and Sciuroidea + Aplodontoidea + Theridomorpha). This topology has led us to endorse Ctenohystrica as the first clade and propose a new taxon, Ischyromyiformes, for the second. Although minimized in our working hypothesis, the homoplasy in dental characters remains significant. However, a number of homoplasic characters reveal structuring in their internal distribution, allowing us to discern evolutionary morphological patterns, notably the pentalophodonty of molars, zygomasseteric complex and incisor enamel microstructure.
Journal of The American Medical Informatics Association, 2002
Rodentia is the largest order of placental mammals, with approximately 2,050 species divided into 28 families. It is also one of the most controversial with respect to its monophyly, relationships between families, and divergence dates. Here, we have analyzed and compared the performance of three nuclear genes (von Willebrand Factor, interphotoreceptor retinoid-binding protein, and Alpha 2B adrenergic receptor) for a large taxonomic sampling, covering the whole rodent and placental diversity. The phylogenetic results significantly support rodent monophyly, the association of Rodentia with Lagomorpha (the Glires clade), and a Glires ϩ Euarchonta (Primates, Dermoptera, and Scandentia) clade. The resolution of relationships among rodents is also greatly improved. The currently recognized families are divided here into seven well-defined clades (Anomaluromorpha, Castoridae, Ctenohystrica, Geomyoidea, Gliridae, Myodonta, and Sciuroidea) that can be grouped into three major clades: Ctenohystrica, Gliridae ϩ Sciuroidea, and a mouse-related clade (Anomaluromorpha, Castoridae ϩ Geomyoidea, and Myodonta). Molecular datings based on these three genes suggest that the rodent radiation took place at the transition between Paleocene and Eocene. The divergence between rodents and lagomorphs is placed just at the K-T boundary and the first splits among placentals in the Late Cretaceous. Our results thus tend to reconcile molecular and morphological-paleontological insights.
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