A new species of Argyromys (Rodentia, Mammalia) from the oligocene of the valley of lakes (Mongolia): its importance for palaeobiogeographical homogeneity across Mongolia, China and Kazakhstan

We describe a new species of Rodentia (Mammalia), Argyromys cicigei sp. nov. from Toglorhoi (fossil bed TGW-A/2a) in Mongolia and Ulantatal (fossil beds UTL 1 and UTL 7) in China. Its tooth morphology differs from the type species Argyromys aralensis from Akespe in Kazakhstan by smaller size and simpler structures. Argyromys has been assigned in different families of Muroidea, such as Tachyoryctoididae and Spalacidae. However, the presence of common characters indicates a closer relationship of Argyromys with the genera of Cricetidae s.l. (subfamilies Eucricetodontinae; Cricetopinae; Cricetodontinae and Gobicricetodontinae among others) from Asia than with the earliest representatives of Spalacidae or the endemic Tachyoryctoididae. Argyromys cicigei sp. nov. possesses a simple anterocone and anteroconid in the upper and lower first molars, respectively, which is characteristic for Cricetidae s.l. It has a flat occlusal surface in worn specimens; weakly-developed posterolophs; an oblique protolophule and metaloph on the upper molars and it lacks a labial anterolophid on the m1. These traits are also typical of the Oligocene genera Aralocricetodon and Plesiodipus, included in the subfamilies Cricetodontinae and Gobicricetodontinae respectively. The cladistic analysis performed here supports this hypothesis. The clade formed by Argyromys species is grouped with other cricetid taxa (s.l). Spalacids, however, form a different clade, as do the tachyoryctoids. Previous authors state that the Aral Formation (Kazakhstan) should be dated to the Oligocene instead of the Miocene, based on the presence of several taxa. The finds of Argyromys in both regions supports the statement that they are closer in age than previously thought. The occurrence of Argyromys in Kazakhstan, Mongolia and China evidences the biogeographic unity of the Central Asian bioprovince during the Oligocene

Cricetidae (Rodentia, Mammalia) from the oligocene of the valley of Lakes (Mongolia): the genera Aralocricetodon, Eocricetodon, Bagacricetodon, Witenia and Paracricetodon

We describe the remains of Aralocricetodon Bendukidze, 1993; Bagacricetodon Gomes Rodrigues et al., 2012; Eocricetodon Wang, 2007; Witenia de Bruijn et al., 2003 and Paracricetodon Schaub, 1925 (Cricetidae, Rodentia, Mammalia) from the Taatsiin Gol and Taatsiin Tsagaan Nuur areas (Mongolia). The studied material (comprising 128 teeth) stems from 9 localities and 23 fossil layers spanning a time interval from ∼33 to ∼24 Ma (early to late Oligocene) and covering the biozones from A to C1. The general dental pattern between the species from the early and late Oligocene differed. The occlusal pattern of the molars was more complicated and the crowns were lower during the early versus late Oligocene. This indicates a change in diet towards more abrasive plants. Several of the studied species were common in both Europe and Asia Minor during the early Oligocene. The species collected from the late Oligocene have also been recorded in Kazakhstan and China. This indicates an interesting biogeographical pattern that merits future study

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

Imaging of subsurface lineaments in the southwestern part of the Thrace Basin from gravity data

Linear anomalies, as an indicator of the structural features of some geological bodies, are very important for the interpretation of gravity and magnetic data. In this study, an image processing technique known as the Hough transform (HT) algorithm is described for determining invisible boundaries and extensions in gravity anomaly maps. The Hough function implements the Hough transform used to extract straight lines or circles within two-dimensional potential field images. It is defined as image and Hough space. In the Hough domain, this function transforms each nonzero point in the parameter domain to a sinusoid. In the image space, each point in the Hough space is transformed to a straight line or circle. Lineaments are depicted from these straight lines which are transformed in the image domain. An application of the Hough transform to the Bouguer anomaly map of the southwestern part of the Thrace Basin, NW Turkey, shows the effectiveness of the proposed approach. Based on geological data and gravity data, the structural features in the southwestern part of the Thrace Basin are investigated by applying the proposed approach and the Blakely and Simpson method. Lineaments identified by these approaches are generally in good accordance with previously-mapped surface faults

Rodents from the Middle Oligocene of Turkish Thrace

Associations of Middle Oligocene rodent teeth are described from five localities in the Lignite-Sandstone Formation of the Ergene basin. The Muroidea are the most abundant as well as the most diverse group in these associations. In rodent faunas of Western Europe the Theridomyoidea dominate. So far representatives of the Theridomyidae have not been found in Thrace and do not seem to have reached Turkey. In addition to seven new (sub)species four new (sub)genera of the Muroidea are defined: Trakymys, Edirnella, Lignite!!a and Kerosinia. The classification of the European Paleogene representatives of this superfamily is discussed and revised. It is concluded that raising a number of taxonomic entities within the Muroidea to a higher rank in the hierachy is in better accordance with our present knowledge of the group than the widely followed classification of Mein and Freudenthal (1971), who include all Tertiary hamsters in one family: the Cricetidae. In addition to Muroidea the rodent associations from Thrace contain teeth of members of the families Eomyidae, Gliridae, Pseudosciuridae, Castoridae and Petauristidae in limited numbers. New species of each of the genera Eomys, Bransatoglis and Glis are described. The faunal details suggest that the five localities correspond to successive levels during an Oligocene time span of approximately one My. Two major zones are apparent but there seem to be possibilities to make a further (sub)zonal subdivision. Our faunas are correlated with part of the MP 23-27 interval of the European standard zonation. The large numbers of Melissiodontidae and Anthracotheriidae suggest vegetated wetland biotopes throughout the investigated interval.

Effect of source and concentration of dietary selenium on laying performance of egg-type breeders and antioxidant status of their offspring under delayed post-hatch feeding [Einfluss von selen-quelle und-konzentration auf die legeleistung von legehennenelterntieren und auf den antioxidativen status ihrer nachkommen bei verzögerter fütterung nach der brut]

2-s2.0-85078364296The present study aimed to evaluate the effect of dietary organic or inorganic selenium (Se) supplementation on laying and hatching performance, egg Se content and liver glutathione peroxidase (GSH-Px) concentration of egg-type breeders as well as their offspring antioxidant status under 36 h post-hatch feed withdrawal. Two hundred and seventy white egg-type breeders were used. The hens were randomly assigned to five dietary treatments. The basal diet contained no supplemental Se (Control). The four treatment groups consisted of two selenium sources (inorganic and organic, Seinorg and Seorg, respectively) and two selenium levels (0.20 and 0.35 mg Se/kg diet). The total analysed Se concentration in the diets was between 0.137 and 0.138 mg/kg for Control, while it was 0.342 and 0.340 mg/kg for 0.20 Seinorg, 0.339 and 0.351 mg/kg for 0.20 Seorg, 0.485 and 0.489 mg/kg for 0.35 Seinorg, 0.481 and 0.495 mg/kg for 0.35 Seorg from 21 to 40 and 41 to 49 weeks, respectively. There was no effect of diets on laying performance, egg quality, and hatchability. Dietary Se supplementation increased egg Se content compared to Control, being higher in eggs from hens fed Seorg than those from hens fed Seinorg. Liver GSH-Px activity of hens fed 0.35 mg Se/kg was higher than in hens fed 0.20 mg/kg Se. On d of hatch and 36 h post-hatch, residual yolk sac Se content of chicks from hens fed 0.35 mg Se/kg was higher than that of chicks from hens fed 0.20 mg/kg Se. After 36 h post-hatch feed withdrawal, plasma and liver GSH-Px activity of chicks from Se groups were higher than in chicks from the Control. It was concluded that dietary maternal Se would provide a protective mechanism for day-old chicks for coping with stressful situations exposed after hatching. © Verlag Eugen Ulmer, Stuttgart.Ministry of Agriculture - Saskatchewan: D/16/A06/P02/02 Ministry of Agriculture of the People's Republic of China, MOA: TAGEM/HAYSÜD/16/A06/P02/02This study was supported by the Ministry of Agriculture, Project Number: TAGEM/HAYS?D/16/A06/P02/02.This study was supported by the Ministry of Agriculture, Project Number: TAGEM/HAYSÜD/16/A06/P02/0