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1. chinaXiv:202008.00033 [pdf]

Taxonomic revision of Anthracokeryx thailandicus ?Ducrocq, 1999 (Anthracotheriidae, Microbunodontinae)?from the Upper Eocene of Thailand

DUCROCQ Stéphane
Subjects: Biology >> Zoology

The anthracotheriid (Mammalia, Cetartiodactyla) species Anthracokeryx thailandicus from the Upper Eocene of Thailand is redescribed in details and a revision of its phylogenetic position within the family is proposed. A combination of important dental differences has been observed that led to attribute the Thai form to a distinct genus, Geniokeryx gen. nov., which represents the third genus included into the Microbunodontinae. The new genus is characterized mainly by its unfused short and deep mandibular symphysis, massive lower and upper premolars, weakly selenodont upper molars that exhibit a protostyle and lack an ectometacristule. The peculiar morphology of its symphysis might have been a sexually dimorphic feature that provided the role of a lateral protection for the enlarged upper canine in males as seen in some Paleogene nimravid carnivorans like Eusmilus. A short review of some Anthracokeryx species from China suggest that A. dawsoni might be synonymous to A. sinensis.

submitted time 2020-08-02 From cooperative journals:《古脊椎动物学报》 Hits47Downloads18 Comment 0

2. chinaXiv:202008.00034 [pdf]

Additional tsaganomyid, cylindrodontid and?ctenodactyloid rodent materials from the Erden Obo?section, Erlian Basin (Nei Mongol, China)

LI Qian
Subjects: Biology >> Zoology

To improve the Paleogene biochronological framework of the Erlian Basin, Nei Mongol?and clarify the diversity of fossil rodents in this region, new tsaganomyids (Cyclomylus lohensis,Coelodontomys asiaticus) from the “Upper White” beds, cylindrodontids (Gobiocylindrodon sp.,Proardynomys sp., and Cylindrodontidae gen. et sp. indet.) from the “Middle Red” and “Lower?Red” beds, and ctenodactyloids (Yuomys sp.) from the “Lower White” beds of the Erden Obo?section are reported. The appearance of C. lohensis and Co. asiaticus from the Erden Obo section?confirms that the age of the “Upper White” beds is Early Oligocene. The “Upper White” beds?of the Erden Obo section and the top bed of the Nom Khong Obo are confirmed to belong to the?same formation by both lithofacies and mammalian fossils. The different kinds of cylindrodontids?found from the different horizons of the Erden Obo section show that the cylindrodontids had a?high diversity and a relative continuous evolution in Eocene Asia.

submitted time 2020-08-02 From cooperative journals:《古脊椎动物学报》 Hits69Downloads43 Comment 0

3. chinaXiv:202008.00035 [pdf]

A new species of Luganoia (Luganoiidae, Neopterygii) from the Middle Triassic Xingyi Biota, Guizhou, China

XU Guang-Hui
Subjects: Biology >> Zoology

新鳍鱼类是辐鳍鱼亚纲中最大的现生类群,中三叠世卢加诺鱼科则是新鳍鱼类干群中的一支,具有特化的头骨和特别高的侧腹鳞片。自1939年命名以来,卢加诺鱼科仅以瑞士东部和南部、意大利北部和西班牙东南部中三叠世海相地层安尼期/拉丁期界线附近发现的瓷鳞卢加诺鱼(Luganoia lepidosteoides)为唯一代表。根据贵州兴义中三叠世晚期(拉丁期)海相地层发现的一块较完整的精美鱼化石,命名了卢加诺鱼属一新种,祥瑞卢加诺鱼(Luganoia fortuna sp. nov.)。新种代表了卢加诺鱼科在亚洲的首次出现,表明此科的生物地理分布比之前认识的要大很多。基于新种与模式种的比较研究,修订了卢加诺鱼属的鉴定特征,揭示了该属过去一些未注意到的解剖学特征,例如存在一对眶前骨,缺少板片状的方颧骨,背鳍基部具有一狭长的裸露身体区域;臀鳍很小,与尾鳍的距离比与腹鳍更近;后匙骨缺失。此外,详细列举了中国新种与欧洲模式种的形态差异,研究结果为了解卢加诺鱼属的形态多样性提供了重要信息。

submitted time 2020-08-02 From cooperative journals:《古脊椎动物学报》 Hits40Downloads13 Comment 0

4. chinaXiv:202004.00001 [pdf]

Reappraisal of Serridentinus gobiensis Osborn & Granger?and Miomastodon tongxinensis Chen:the validity of Miomastodon

WANG Shi-Qi; ZHANG Xiao-Xiao; LI Chun-Xiao?
Subjects: Biology >> Zoology

The elephantimorph proboscideans, Serridentinus gobiensis Osborn & Granger, 1932, and Miomastodon tongxinensis Chen, 1978, from the Middle Miocene of northern China, were revised as Zygolophodon gobiensis (Osborn & Granger, 1932). However, their phylogenetic positions are still being debated because of their intermediate morphology between the typical bunodont (Gomphotheriidae) and zygodont (Mammutidae) elephantimorphs. In the present paper, we compare their dental and mandibular morphology with that of the Eurasian Z. turicensis, Gomphotherium subtapiroideum, and G. tassyi, as well as the North American Mio. merriami and G. productum. It appears that S. gobiensis and Mio. tongxinensis share with Mio. merriami the slightly more bunodont molar morphology than that of Z. turicensis, e.g., the thicker enamel, thicker pretrite crescentoids, higher interlophid enamel pillars in buccal view, and the narrower contour majorly caused by the narrower posttrite half loph(id)s. S. gobiensis and Mio. merriami also possess an “erected oval cross-sectioned mandibular tusk”, in which the cross-section is mediolaterally compressed (dorsoventral diameter being larger than the mediolateral one). Whereas, in Z. turicensis and G. productum, the mandibular tusk is “laid oval cross-sectioned”, in which the cross-section is dorsoventrally compressed (dorsoventral diameter is smaller than the mediolateral one). Therefore, it is reasonable to revive the genus Miomastodon Osborn, 1922, which contains the species that were previously attributed to Zygolophodon, but they have relatively bunodont molar morphology (i.e., the robust type of the Z. turicensis group). The mandibular tusk with erected?oval cross-section seems to be a synapomorphy of Miomastodon species. Furthermore, the molar morphology of G. subtapiroideum and G. tassyi also exhibits intermediate status between the typical bunodonts and zygodonts. However, the mandibular symphysis of G. subtapiroideum and G. tassyi is stronger than that of Miomastodon, and the mandibular tusk is pyriform cross-sectioned. The validity of Miomastodon and G. subtapiroideum/tassyi obscures the boundary between the Gomphotheriidae and Mammutidae, and suggests that the evolutions of the Gomphotheriidae and?Mammutidae are deeply involved in with each other, rather than straightforwardly detached. This phenomenon has been revealed by a collagen sequence analysis among Notiomastodon, Mammut, and extant elephants, which should be further studied.

submitted time 2020-03-31 From cooperative journals:《古脊椎动物学报》 Hits4698Downloads577 Comment 0

5. chinaXiv:202004.00002 [pdf]

New material of Cervidae (Artiodactyla, Mammalia) from?Xinyaozi Ravine in Shanxi, North China

DONG Wei; BAI Wei-Peng; PAN Yue; LIU Wen-Hui
Subjects: Biology >> Zoology

Many cervid specimens were uncovered during the field exploration for Nihewan beds?at the beginning of the 1980s from Taijiaping, Shuichongkou and Dazhuangke localities along?Xinyaozi Ravine at Nangaoya Township of Tianzhen County, Shanxi Province in North China.?Recent studies on the cervid material identified seven species of Cervidae in total: Muntiacus?bohlini, Cervavitus cf. C. huadeensis, Axis shansius, Nipponicervus elegans, Elaphurus?davidianus predavidianus, E. bifurcatus from the Early Pleistocene deposits at Taijiaping and?Shuichongkou localities, and Cervus (Elaphus) elaphus from uncertain horizon at Dazhuangke. At?least the previous six species of cervids were from Nihewan Formation (Nihewanian or equivalent?to European middle and late Villafranchian), i.e. the Early Pleistocene, in Sangganhe Basin area.Cervavitus cf. C. huadeensis and A. shansius were survivors from the Late Neogene; M. bohlini,N. elegans, E. davidianus predavidianus and E. bifurcatus are new forms of the Early Pleistocene.If Dazhuangke horizon can be dated as those of Shuichongkou and Taijiaping localities, the appearance of elaphoid cervids could be traced back to the Early Pleistocene, and the evolution of?elaphoid antler would start from absence to presence of bez tine. The presence of Elaphurus and?Nipponicervus in mainland China and Japanese archipelago implies further that the sea level was?dropped down that these cervids could migrate from the mainland to the islands. The abundance?of folivorous cervid specimens in the Xinyaozi Ravine area indicates the existence of a certain?scale of forested environment in Sangganhe Basin area during the Early Pleistocene.

submitted time 2020-03-31 From cooperative journals:《古脊椎动物学报》 Hits4242Downloads537 Comment 0

6. chinaXiv:202004.00003 [pdf]

A new species of Amynodontopsis (Perissodactyla:?Amynodontidae) from the Middle Eocene of Jiyuan,?Henan, China

WANG Xiao-Yang; WANG Yuan-Qing; ZHANG Rui; ZHANG Zhong-Hui; ?LIU Xiao-Ling; REN Li-Ping
Subjects: Biology >> Zoology

An adult amynodont skull, collected from the Middle Eocene Niezhuang Formation of Jiyuan Basin (Henan, China), is recognized as a new species Amynodontopsis jiyuanensis sp. nov. The specimen possesses the typical features of the genus Amynodontopsis, such as a dolichocephalic skull with elevated roof, premaxilla-nasal contact, large preorbital fossa extending posteriorly medial to the orbit, inner surface of anterior orbital bar concave in continuation with the preorbital fossa, antecrochet usually presented on M1, and metastyle of M3 strongly deflected labially. A. jiyuanensis is diagnosed by a combination of the following characters: long nasals, nasal process of premaxilla extending far back laterally below the nasal and excluding the maxilla from the border of external nares, nasal notch above the post-canine diastema, more transverse and proportionally longer protoloph and metaloph on upper molars. Comparison with known species of Amynodontopsis indicates that it is the most primitive one in the genus, due to the possession of primitive characters. Associated fossil mammals support a correlation of the strata bearing A. jiyuanensis with the Shara Murun Formation of the Erlian Basin, Nei Mongol, China, namely the Middle Eocene Sharamurunian Asian Land Mammal Age (ALMA), prior to all other known Amynodontopsis species. The earlier geologic age and primitive morphological features of A. jiyuanensis suggest that Amynodontopsis has an Asian origin in the Middle Eocene and later immigrated into North America.

submitted time 2020-03-31 From cooperative journals:《古脊椎动物学报》 Hits4473Downloads546 Comment 0

7. chinaXiv:202004.00004 [pdf]

A Late Miocene Huerzelerimys (Rodentia: Muridae) skull?from Hezheng, Gansu, China

WANG Ban-Yue; QIU Zhan-Xiang; ?LI Lü-Zhou
Subjects: Biology >> Zoology

A skull with mandible and several cervicals of a new species of Huerzelerimys, H.asiaticus, collected from the Late Miocene Liushu Formation in Linxia Basin, Gansu Province,is described in this paper. The skull is the first one ever found for the genus Huerzelerimys. Its?main characters are: size small; skull broad and short with stout rostrum; interorbital roof narrow;premaxillary laterodorsal crest well developed; frontal crests weak and subparallel; incisive?foramina long, with their posterior ends lined up with anterior root of M1; posterior palatal?foramina located mesial to M2; caudal border of hard palate lying posterior to M3;interpterygoid?foramen absent; alisphenoid canal bony; bulla large and inflated; internal carotid foramen located?near the basilar tubercle; mandible having low horizontal ramus and deeply concave diastema;?anterior end of masseteric ridge lined up with anterior margin of m1; mental foramen situated?slightly anterior to masseteric ridge and anteroventral to m1, near to mandibular diastema; upper?incisors orthodont; M1 having slightly anteriorly located t1; in M1 and M2 t6 and t9 connected by?distinct crest and t12 crest-like; t1 and t3 of M2 and t1 of M3 connected to t5; M3 having t3 and?a large isolated t8; small Acc of m1 connected with both Alc and Abc; m1 and m2 having distinct?buccal cingula, larger c2 attached to protoconid, and low crest-like posterior heel; m2 and m3?having isolated Abc; c1 absent in m3. The evolutionary level of the described skull tends to show?that the age of the upper part of the Liushu Formation yielding H. asiaticus may belong to late Bahean, corresponding to European upper MN11 or lower MN12.

submitted time 2020-03-31 From cooperative journals:《古脊椎动物学报》 Hits4335Downloads457 Comment 0

8. chinaXiv:201911.00045 [pdf]

棉蚜生活史类型及其越冬寄主研究进展

晁文娣
Subjects: Biology >> Zoology

棉蚜(Aphis gossypii)是一种生活史较复杂的杂食性农业害虫,由于在不同地域气象因素和植被的差异,限制了其生活史类型和越冬寄主种类。分析全球研究棉蚜生活史策略文献,从棉蚜能否以卵越冬为主线,分析世界不同区域棉蚜的两种生活史类型,对棉蚜异寄主全周期型这一生活史策略的原生寄主进行梳理。通过分析棉蚜在不同区域的生活史策略及其越冬寄主,有助于深入研究农作物保护策略,为棉蚜的系统化防治奠定理论基础。

submitted time 2019-11-14 From cooperative journals:《干旱区研究》 Hits996Downloads524 Comment 0

9. chinaXiv:201910.00010 [pdf]

新疆阿尔泰山鞘翅目昆虫物种多样性研究

张东康
Subjects: Biology >> Zoology

依据2015年对新疆阿尔泰山昆虫资源的科考结果,结合新疆大学生命科学与技术学院昆虫标本馆有关阿尔泰山鞘翅目的馆藏标本,对阿尔泰山6个林场的鞘翅目昆虫进行标本鉴定和数据统计分析。整理阿尔泰山鞘翅目昆虫共2 061号,隶属于22科85属129种。多样性分析表明,优势类群为叶甲科和金龟科,合计占鞘翅目物种总数的43.76%(31.44%,12.32%),以薄翅萤叶甲Pallasiola absinthii (Pallas),粗糙弯边蜣螂Cymnopleurus flagellates (Fabricius)为优势种。科级Shannon-Wiener指数以富蕴林场最高(2.18),福海林场次之(2.17);种级Shannon-Wiener指数以福海林场最高(3.01)。种级和科级Margalef指数均以福海林场最高(2.79,7.94);福海林场和富蕴林场之间的科级相似性系数最高(0.17);由于布尔津林场和阿尔泰林场的植被和生境类型较相似,故二者种级相似性系数最高(0.82)。研究结果表明鞘翅目昆虫在新疆阿尔泰山不同林场的种类和数量存在明显差异。

submitted time 2019-10-11 From cooperative journals:《干旱区研究》 Hits4280Downloads623 Comment 0

10. chinaXiv:201908.00095 [pdf]

First report of immature feathers in juvenile?enantiornithines from the Early Cretaceous Jehol avifauna

Jingmai K. O’CONNOR; Amanda FALK; WANG Min; ZHENG Xiao-Ting
Subjects: Biology >> Zoology

Molting—the process replacing one plumage with another—is a critically important?biological function in Aves. This process annually replaces the feather coat, damaged by normal?wear and tear, produces ontogenetic changes in feathering, and produces alternate breeding?plumages associated with reproductive activity in adults. Immature, growing feathers are?encased in a keratinous sheath, giving them a narrow, tubular, and featureless appearance. The?complete loss of the sheath indicates the feather is mature. Despite the wealth of integumentary?data published from the Jehol Biota, immature feathers have never been definitively reported,?although they may potentially be preserved in a juvenile specimen of the non-avian oviraptorosaur?theropod dinosaur Similicaudipteryx from the 120 Ma Jiufotang Formation. A developing?feather has been reported in a 99 Ma enantiornithine neonate preserved in Burmese amber, in?which three-dimensional preservation makes interpretations of integumentary structures more?straightforward. Here we report on probable immature feathers in four juvenile enantiornithines?(Aves: Ornithothoraces) from the Jehol Group. As observed in developing feathers in extant?birds, the purported immature fossil feathers appear proximally narrow and featureless with?barbs protruding only distally. Based on our observations, we suggest that similar-appearing?feather structures preserved on the manus and tibiotarsus in the holotype of the enantiornithine?Cruralispennia multidonta may alternatively be interpreted as immature feathers. The presence?of immature feathers in combination with sexually dimorphic ornamental feathers in juvenile?enantiornithines suggests the complex molting patterns of Neornithes, in which such ornaments?only appear after several years (following several molts) when reproductive activity is achieved,?are limited to a subset of crownward avians.

submitted time 2019-08-27 From cooperative journals:《古脊椎动物学报》 Hits6270Downloads562 Comment 0

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