Species Of Cricetid Rodents Research Articles

Chigger Mites (Acariformes: Trombiculidae) of Chiloé Island, Chile, With Descriptions of Two New Species and New Data on the Genus Herpetacarus.

Three species of chigger mites are recorded in our collections from four species of cricetid rodents on Chiloé Island (southern Chile, Los Lagos Region), an area endemic to scrub typhus (Orientia sp.). Two species are described as new-Herpetacarus (Abonnencia) eloisae sp. nov. and Quadraseta chiloensis sp. nov. One species, Paratrombicula goffiStekolnikov and González-Acuña 2012, is for the first time recorded on a mammal host (one species of cricetid rodent), and its distribution is extended to the Los Lagos Region of Chile. The genus ProschoengastiaVercammen-Grandjean, 1967 is synonymized with the subgenus Herpetacarus (Abonnencia)Vercammen-Grandjean, 1960, and four new combinations are established: Herpetacarus (Abonnencia) herniosa (Brennan and Jones, 1961), comb. nov., Herpetacarus (Abonnencia) insolita (Brennan and Jones, 1961), comb. nov., Herpetacarus (Abonnencia) macrochaeta (Brennan and Jones, 1961), comb. nov., and Herpetacarus (Abonnencia) antarctica (Stekolnikov and Gonzalez-Acuña, 2015), comb. nov.

Evolution of the genus Eucricetodon (Rodentia, Mammalia) from the Valley of Lakes (Mongolia): a taxonomical description and update on the stratigraphical distribution

The Oligocene fossil deposits from Valley of Lakes in Central Mongolia have provided a wealth of rodent fossils. Among these, cricetids are a very important part. To date, only the Miocene genera have been described in detail. Here, we focus on the Oligocene genus Eucricetodon from this region. Eucricetodontinae are the most abundant fossils in the Oligocene Valley of Lakes faunas. The present study consists of the description of five species of cricetid rodents from 43 localities ranging in age from the early Oligocene to the early-late Oligocene. In addition to Eucricetodon asiaticus described in Mongolia in 1923, we have found Eucricetodon bagus and Eucricetodon jilantaiensis that were described from Nei Mongol and Eucricetodon occidentalis discovered in Kazakhstan. This taxonomical study provides new information regarding the evolution of the Cricetidae in Central and Eastern Asia during the Oligocene and, more particularly, regarding their phylogenetic relationships and the evolutionary trends.

Paciculus walshi, new species, (Rodentia, Cricetidae), the origin of the Cricetidae and an Oligocene intercontinental mammal dispersal event

Cricetid rodents have a very high reproductive capacity and usually a short life span, measured in months rather than years. Many of them are also non-gregarious, searching for new resources outside the confines of their present habitat. These features provide cricetid rodents with valuable attributes as agents of historical biology. We describe a new species of cricetid rodent, Paciculus walshi, an Oligocene cricetid rodent in North America; we characterise its enamel microstructure and dental features and review its relationship with other cricetid rodents globally, to place it within the framework of Oligocene historical biology.

Megacricetodon vandermeuleni, sp. nov. (Rodentia, Mammalia), from the Spanish Miocene: a new evolutionary framework for Megacricetodon

ABSTRACT A new species of cricetid rodent, Megacricetodon vandermeuleni, sp. nov., is described from the local zone Db, middle Aragonian, from the Calatayud-Montalbán Basin and the Loranca Basin (Spain). The large-sized Megacricetodon is characterized by the elongated anteroconid and anterolophulid on m1 and the robust and swollen cusps. Comparisons with other species of similar size and morphology are discussed. We consider M. bezianensis a valid species, based on the morphological differences with M. gersii. We propose a closely related group of Megacricetodon species that includes M. aff. collongensis, M. bavaricus, M. aff. bavaricus, M. bezianensis, M. lappi, M. aunayi, and M. vandermeuleni, nov. sp. The new species is of importance for Spanish biostratigraphy and the proposed Megacricetodon group is very useful for European faunal correlations and timing of migration events. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP

New Species of Cricetid Rodents (Mammalia) from the Late Miocene (Hemphillian) Previously Referred toPeromyscus pliocenicusWilson

ABSTRACT Specimens previously identified as the Hemphillian cricetid Basirepomys pliocenicus (Wilson, 1937) (=Peromyscus pliocenicus Wilson, 1937) by Korth and De Blieux (2010) have been re-examined, and several distinct species are here recognized. Specimens from the early Hemphillian Rome fauna of Oregon are referred to a new, more primitive species of Basirepomys Korth and De Blieux, 2010, here named Basirepomys romensis, new species, which differs from other species of the genus in having lower-crowned cheek teeth and incomplete alternation of cusps on some molars. Specimens from the early Hemphillian Juniper Creek and Little Valley faunas of Oregon are referable to Paronychomys Jacobs, 1977, rather than Basirepomys, and represent a new species, Paronychomys shotwelli, which is distinguished from other species of the genus by its larger size and relatively longer lower third molar. A specimen previously referred to Peromyscus pliocenicus from the early Hemphillian of Kansas is referable to Paronychomy...

A new genus and species of rodent from the Brazilian Atlantic Forest (Rodentia: Cricetidae: Sigmodontinae: Oryzomyini), with comments on oryzomyine biogeography

We describe in this paper a new genus and species of cricetid rodent from the Atlantic Forest of Brazil, one of the most endangered eco-regions of the world. The new form displays some but not all synapomorphies of the tribe Oryzomyini, but a suite of unique characteristics is also observed. This new forest rat possesses anatomical characteristics of arboreal taxa, such as very developed plantar pads, but was collected almost exclusively in pitfall traps. Phylogenetic analyses of morphological (integument, soft tissue, cranial, and dental characters) and molecular [nuclear – Interphotoreceptor retinoid binding protein (Irbp) – and mitochondrial – cytochrome b– genes] datasets using maximum likelihood and cladistic parsimony approaches corroborate the inclusion of the new taxon within oryzomyines. The analyses also place the new form as sister species to Eremoryzomys polius, an Andean rat endemic to the Maranon valley. This biogeographical pattern is unusual amongst small terrestrial vertebrates, as a review of the literature points to few other similar examples of Andean–Atlantic Forest pairings, in hylid frogs, Pionus parrots, and other sigmodontine rodents. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161, 357–390.

Small Rodent Populations and Conifer Seedling Damage on a Reclaimed Area in West Central Alberta

Small rodent populations and conifer seedling survival were monitored on a reclaimed area in west central Alberta from September 1979 to September 1985. Although several species of cricetid rodents and shrews were captured during the live-trapping program, only meadow voles (Microtus pennsylvanicus) and deer mice (Peromyscus maniculatus) occurred in sufficient number to monitor annual changes in abundance. Meadow voles increased rapidly on the reclaimed area from 1979–1981, remained at high numbers until 1984, then declined sharply in 1985. Deer mice increased to moderate numbers from 1979–1981 and declined gradually until 1983. By 1984–1985, very few deer mice were present.Two species of conifer seedlings, lodgepole pine (Pinus contorta) and white spruce (Picea glauca) were planted on the reclaimed area in 1979 and 1980. Numbers of seedlings killed or damaged by small rodents, primarily by girdling, increased sharply in 1981 and remained at high levels through to 1984. Significant correlations between the percentage of the annual mortality of seedlings attributed to small rodents or the percentage of live seedlings damaged by small rodents, and the abundance of meadow voles the previous winter, indicate that the amount of mortality and damage to seedlings in this reclamation area is in part determined by the overwintering abundance of meadow voles. This is in direct agreement with conclusions from similar studies in other areas of North America and Europe.

Evolutionary relationships among Eimeria spp. (Apicomplexa) infecting cricetid rodents

Evolutionary relationships among seven species of Eimeria from five species of cricetid rodents (Neotoma albigula, Peromyscus eremicus, Peromyscus leucopus, Peromyscus maniculatus, Peromyscus truei) were examined by phenetic and cladistic analysis of oocyst structure, life-history data, and isozyme banding patterns. Phenetic and cladistic analyses revealed two distinct lineages of Eimeria spp.: type A Eimeria spp. (Eimeria albigulae, Eimeria arizonensis, Eimeria peromysci), characterized by subspheroid oocysts with rough outer walls, lemon-shaped sporocysts, oocyst residua, prominent Stieda bodies, and two obvious wall layers; and type B Eimeria spp. (Eimeria delicata, Eimeria lachrymalis, Eimeria ladronensis, Eimeria lange-barteli), characterized by ellipsoid oocysts with one obvious, smooth wall, no residuum, and ellipsoid or teardrop-shaped sporocysts with thin walls and tiny Stieda bodies. Cladistic analysis of the type A and type B data sets, using Eimeria nieschulzi and Eimeria papillata (hosts: Rattus norvegicus and Mus musculus, respectively) for outgroup comparison, showed the more derived nature of Eimeria spp. infecting Peromyscus spp. relative to those species infecting N. albigula. Comparison of parasite phylogenies to a hypothesized phylogeny for the hosts based on enzyme electrophoretic data revealed patterns of host–parasite phylogenetic congruence that were most evident at the generic level of the hosts.

The Discovery of Chiggers (Acarina, Trombiculidae) in the Nasal Passages of Cricetid Rodents from California, with Descriptions of Two New Species

Two new chiggers from the intranasal passages of cricetid rodents from Joshua Tree National Monument, California are Microtrombicula nasalis sp. n. off Peromyscus eremicus, Peromyscus crinitus, Peromyscus truei, and Neotoma lepida; and Microtrombicula wrenni sp. n. off Peromyscus eremicus and Peromyscus crinitus. These species are closely related to Microtrombicula ornata (Loomis and Lipovsky) and Microtrombicula merrihewi (Loomis and Lipovsky) from the central United States. The presence of chiggers in the nasal passages of vertebrates was reported initially by Fain and Vercammen-Grandjean in 1953 from mammals of Africa. More recently Audy and Nadchatram (1957) described intranasal chiggers from rats in Malaysia; Southcott (1957) announced the discovery of a new chigger from the respiratory passages of a Pacific sea snake, and Yunker and Jones (1961) described two new genera of intranasal chiggers from bats of Panama. The latter were the first to be reported from the order Chiroptera and from the New World. The above reports prompted examination of the nasal passages of small mammals, which resulted in the discovery of two species of intranasal chiggers in mice and rats (family Cricetidae) of California. These chiggers were found in the anterior portion of the nasal passages of four species of cricetid rodents: Neotoma lepida Thomas, Desert Wood Rat; Peromyscus crinitus (Merriam), Canyon Mouse; Peromyscus eremicus (Baird), Cactus Mouse; and Peromyscus truei (Shufeldt), Pifion Mouse-trapped in late December 1961 and early February 1962 in Joshua Tree National Monument, California. The total number of larvae of both species per host varied from 1 to 8 (avg. 3.5 larvae), except for a single Cactus Mouse infested with 93 larvae. This mouse contained both species of chiggers, including more than 60 fully engorged larvae in the nasal passages. The presence of unengorged larvae in this mouse seems to indicate that February is a period of activity of the free-living larvae. S udies of these chiggers revealed that they represent two new species which seem to belong in the genus Microtrombicula Ewing, as redefined by Vercammen-Grandjean (1960). They are closely related to Microtrombicula ornata (Loomis and Lipovsky) and Microtrombicula errihewi (Loomis and Lipovsky) originally placed in the genus Trombicula and later in the ornata group (Loomis, 1956: 1324). T e species M. merrihewi was obtained from bats in Oklahoma and M. ornata from cricetid rodents taken in Kansas and Colorado. They were reported as being found in the ears of their hosts. From available information on the r recovery, these chiggers seem to have been obtained from detergent water placed under the living host and from washing the dead mammals. They were not taken directly f om the ears. In light of the discovery of these new, closely related species in the nasal passages, it seems probable that Microtrombicula ornata and M. merrihewi are also intra-