Dispersal,vicariance, and the Late Cretaceous to early tertiary land mammal biogeography from South America to Australia

A review of paleontological, phyletic, geophysical, and climatic evidence leads to a new scenario of land mammal dispersal among South America, Antarctica, and Australia in the Late Cretaceous to early Tertiary epochs. New fossil land vertebrate material has been recovered from all three continents in recent years. As regards Gondwana, the present evidence suggests that monotreme mammals and ratite birds are of Mesozoic origin, based on both geochronological and phyletic grounds. The occurrence of monotremes in the early Paleocene (ca. 62 Ma) faunas of Patagonia and of ratites in late Eocene (ca. 41-37 m.y.) faunas of Seymour Island (Antarctic Peninsula) probably is an artifact of a much older and widespread Gondwana distribution prior to the Late Cretaceous Epoch. Except for South American microbiotheres being australidelphians, marsupial faunas of South America and Australia still are fundamentally disjunct. New material from Seymour Island (Microbiotheriidae) indicates the presence there of a derived taxon that resides in a group that is the sister taxon of most Australian marsupials. There is no compelling evidence that dispersal between Antarctica and Australia was as recent as ca. 41 Ma or later. In fact, the derived marsupial and placental land mammal fauna of Seymour Island shows its greatest affinity with Patagonian forms of Casamayoran age (ca. 51–54 m.y.). This suggests an earlier dispersal of more plesiomorphic marsupials from Patagonia to Australia via Antarctica, and vicariant disjunction subsequently. This is consistent with geophysical evidence that the South Tasman Rise was submerged by 64 Ma and with geological evidence that a shallow water marine barrier was present from then onward. The scenario above is consistent with molecular evidence suggesting that australidelphian bandicoots, dasyurids, and diprotodontians were distinct and present in Australia at least as early as the 63-Ma-old australidelphian microbiotheres and the ancient but not basal australidelphian,Andinodelphys, in the Tiupampa Fauna of Bolivia. Land mammal dispersal to Australia typically has been considered to be at a low level of probability (e.g., by sweepstakes dispersal). This study suggests that the marsupial colonizers of Australia included already recognizable members of the Peramelina, Dasyuromorphia, and Diprotodontia, at least, and entered via a filter route rather than by a sweepstakes dispersal.To whom correspondence should be addressed.     

Echinocampidae fam. nov., a new family of Late Jurassic-Early Cretaceous radiolarians of Arctic Siberia

When studying Late Jurassic-Early Cretaceous radiolarians from the Nordvik section (Arctic Siberia), unique morphotypes of multicyrtoid nassellarians with many horns in the apical part of the shell, which continue the rays A, V, 2l, D, and 2L of the cephalic spicule, were recorded. These morphotypes are assigned to a new family, Echinocampidae fam. nov., including three new genera (Echinocampe gen. nov., Nordvikella gen. nov., and Arctocapsula gen. nov.) and eight new species. The family Echinocampidae was probably restricted to high latitudes and belonged to the boreal fauna of the terminal Jurassic and the basal Cretaceous.     

Paleoenvironmental and paleobiogeographical implications of the microfossil assemblage from the Late Cretaceous intertrappean beds of the Manawar area,District Dhar,Madhya Pradesh,Central India

Abstract

An assemblage of microfossils consisting of non-marine ostracods (Cypridopsis, Gomphocythere, Zonocypris, Eucypris, and Frambocythere), charophyte gyrogonites (Platychara), molluscs (Viviparus, Valvata, and Lymnaea), and fish remains (mainly Phareodus), is here reported from a new intertrappean locality near the town of Manawar, District Dhar, Madhya Pradesh, Central India. The biotic component recovered suggests a Late Cretaceous (Maastrichtian) age for the intertrappean deposit near Manawar. Paleoenvironmentally, the overall biotic assemblage recovered indicates the presence of a freshwater palustrine/lacustrine depositional system connected to a low energy stream/river. Paleobiogeographically, the known high diversity of ostracod genera, especially Eucypris, Cypridopsis, and Gomphocythere, hints at endemism within the Indian Subcontinent during the Late Cretaceous (Maastrichtian). However, the cosmopolitan distribution of the charophyte genus Platychara in the K-Pg interval across the globe (Africa, Europe, and America) and its absence in the Upper Cretaceous of China and Mongolia is quite intriguing.     

Taphonomy and systematics of a new Late Cretaceous verrucid barnacle (Cirripedia,Thoracica) from Canterbury,New Zealand

Abstract: Cirripede remains (Thoracica, Verrucomorpha), found associated with the mosasaur Prognathodon waiparaensis  Welles and Gregg, 1971 in glauconitic sands of the Late Cretaceous Conway Formation exposed along the Waipara River bank (mid‐Canterbury, New Zealand), are identified as a new species, Verruca sauria sp. nov. On the basis of taphonomy, it is deduced that these verrucids grew on a postmortem accumulation of mosasaur bones under very quiescent conditions. The current amphitropical distribution of the earliest known verrucids, i.e. V. sauria sp. nov., V. prisca  Bosquet, 1854 , V. pusilla  Bosquet, 1857 and V. tasmanica  Buckeridge, 1983 , is rationalized in the light of Tethyan palaeogeography.     

New crested specimens of the Late Cretaceous pterosaurNyctosaurus

Two recently collected specimens of the Late Cretaceous pterosaurNyctosaurus differ from all previously known specimens in the possession of a large branching cranial crest. The crest extends upward and backward from the posterior skull roof and is nearly three times the length of the skull proper. Despite the large crest, the specimens do not differ significantly in morphology from previously known specimens ofNyctosaurus, and do not seem to represent a new species ofNyctosaurus. The specimens suggest that the cranial crest was developed late in ontogeny, which is consistent with the interpretation of pterosaur cranial crests as intraspecific display structures.      

Biotic interaction and synecology in a Late Cretaceous coral-rudist biostrome of southeastern Spain

A coral-rudist biostrome exposed in Campanian limestones near the village of Tabernas de Valldigna in south-east Spain was analysed with respect to its palaeontology, sedimentology and palaeoecology. Special attention was given to possible evidence for synecological interactions between corals and rudists. Changes in the rudist shell accretion process are evident in some polished slabs and thin sections and resulted from in vivo contact with coral-colonies. These unusual balcony-like shell protuberances exist where the rudist’s commissure was in contact with corals. They likely represent defence-reactions of rudists against the coral cnidia. Nevertheless, the fossil record of these biotic interactions is rare. This may be due to different growth-rates of rudists and corals, differing shape and size of interacting areas, or different life-spans. In consequence, the discrete ‘window’ of intergroup biotic interaction was small. Sedimentation and resuspension rates were high in the biostrome and corals only established pioneer associations under these unfavourable conditions. A higher diversity of corals is reached, however, when rudists are present. This increase in diversity resulted from the availability of additional ecological niches such as rudist-shell hard substrates and elevation above mobile sediment surface. Rudists on the other hand, received support from stabilisation of their shells through coral encrustation and framework building. In consequence, both groups benefited from their co-existence.     

Island life in the Cretaceous - faunal composition,biogeography, evolution,and extinction of land-living vertebrates on the Late Cretaceous European archipelago

The Late Cretaceous was a time of tremendous global change, as the final stages of the Age of Dinosaurs were shaped by climate and sea level fluctuations and witness to marked paleogeographic and faunal changes, before the end-Cretaceous bolide impact. The terrestrial fossil record of Late Cretaceous Europe is becoming increasingly better understood, based largely on intensive fieldwork over the past two decades, promising new insights into latest Cretaceous faunal evolution. We review the terrestrial Late Cretaceous record from Europe and discuss its importance for understanding the paleogeography, ecology, evolution, and extinction of land-dwelling vertebrates. We review the major Late Cretaceous faunas from Austria, Hungary, France, Spain, Portugal, and Romania, as well as more fragmentary records from elsewhere in Europe. We discuss the paleogeographic background and history of assembly of these faunas, and argue that they are comprised of an endemic ‘core’ supplemented with various immigration waves. These faunas lived on an island archipelago, and we describe how this insular setting led to ecological peculiarities such as low diversity, a preponderance of primitive taxa, and marked changes in morphology (particularly body size dwarfing). We conclude by discussing the importance of the European record in understanding the end-Cretaceous extinction and show that there is no clear evidence that dinosaurs or other groups were undergoing long-term declines in Europe prior to the bolide impact.     

Oxalis jiayinensis,a new species of the Late Cretaceous from Heilongjiang,NE China

Oxalis jiayinensis, sp. nov., is described from the Late Cretaceous (TuronianSenonian) in Jiayin County, Heilongjiang Province, northeastern China. The seed is about 1 mm long, less than 1 mm in diameter, crescentic with obtuse apices and 9～10 transverse ribs. The seed wall is composed of equiaxial, strongly thickened sclereids. The fossil repre-sents the oldest occurrence of the family Oxalidaceae in the world.     

A new late Cretaceous azhdarchid (Pterosauria,Azhdarchidae) from the Volga Region

A new azhdarchid genus and species, Volgadraco bogolubovi gen. et sp. nov., is described based on an anterior fragment of the mandibular symphysis (mandibular beak) and some postcranial elements from the Rybushka Formation (Upper Cretaceous, Lower Campanian) of the Shirokii Karamysh 2 locality, Saratov Region. The new taxon is intermediate in size and vascularization of the mandibular beak between medium-sized Turonian-Santonian azhdarchids (Azhdarcho, Bakonydraco) and the giant Maastrichtian azhdarchid Quetzalcoatlus.     

中国东北晚白垩世酢酱草属（酢酱草科）一新种：嘉荫酢酱草

本文描述了发现于中国黑龙江省嘉荫县晚白垩世(土仑期至赛诺期)的酢酱草科酢酱草属新种 Oxalis jiayinensis Feng,Liu,Song et Ma;炭化种子长约1 mm,宽不足1mm;新月形,两端钝;表面具9 ～10条横脊;种皮石细胞等轴、细胞壁明显加厚。该化石种是酢酱草科在地质时期迄今最早的代表。     

山西天镇晚白垩世一新鸭嘴龙超科恐龙（英文）

记述了山西天镇晚白垩世灰泉堡组发现的一鸭嘴龙超科恐龙新属种:天镇大同龙Datonglong tianzhenensis gen.et sp.nov.。标本为一保存较完好的右侧齿骨并带牙齿。与其他鸭嘴龙超科恐龙不同,大同龙每个齿槽有两个功能齿,而且舌面齿冠上嵴的发育也具有独特的特征组合(主嵴向远中方向偏移;次嵴发育;无其他附嵴;主嵴上半段略后弯)。对比研究发现,在较进步的非鸭嘴龙科鸭嘴龙超科类群中齿骨和牙齿的演化过程复杂,许多鸭嘴龙科的特征在这些类群中时而出现,如:巴克龙Bactrosaurus齿冠具有较大的高/宽比;吉尔摩龙Gilmoreosaurus齿冠上只有一个主嵴和纤弱的附嵴;张衡龙Zhanghenglong齿冠上主嵴中置;南宁龙Nanningosaurus下颌冠状突前倾;大同龙Datonglong每个齿槽有两个功能齿。这表明为了获得更有效的牙齿咀嚼方式,在鸭嘴龙科起源前它的姐妹群们曾进行过多种尝试;这也告诫我们,受大量趋同演化的影响,要厘清这些类群间的关系并非易事。     

New jewel beetles (Coleoptera: Buprestidae) from the Cretaceous of Russia,Kazakhstan, and Mongolia

A new jewel beetle genus, with one species (Cretofrontolina kzyldzharica gen. et sp. nov.) from the Upper Cretaceous of Kazakhstan is described based on a body; and three new species of the formal genus Metabuprestium are described based on isolated elytra: Metabuprestium sibiricum sp. nov. and M. arkagalense sp. nov. come from the Arkagala locality (Upper Cretaceous of Russia) and M. ichbogdense sp. nov. is from the Shar Tologoi locality (Lower Cretaceous of Mongolia).     

New mammal remains from the Late Cretaceous Bostobe Formation (Northeast Aral Sea Region,Kazakhstan)

Four recently collected mammal specimens from the Upper Cretaceous (Santonian–?Campanian) Bostobe Formation in the northeastern Aral Sea Region, Kazakhstan are attributed to Asioryctitheria indet. (an edentulous dentary fragment) and the zhelestid Parazhelestes sp. cf. P. mynbulakensis (a maxillary fragment with a double-rooted canine, an M1, and a dentary fragment including m3). These new records double the known mammal fauna from this formation, which previously included the zhelestid Zhalmouzia bazhanovi and Zhelestidae indet. The taxonomic and ecological structure of the mammal assemblage from the Bostobe Formation can, on present evidence, be considered close to the other eutherian dominated Late Cretaceous mammal assemblages of Central Asia. This region is important in particular in the search for Late Cretaceous ancestors of crown-group eutherian mammal clades (Placentalia).     

A new subfamily of ichneumonids from the Lower Cretaceous of Transbaikalia and Mongolia (Insecta: Hymenoptera: Ichneumonidae)

A new subfamily of ichneumonids, Palaeoichneumoninae, is described from the Lower Cretaceous of Transbaikalia (Baisa locality) and Mongolia (Bon Tsagan and Kholbotu Gol localities). The new subfamily is intermediate between the archaic subfamily Tanychorinae and the Recent Ichneumonidae. It includes 12 new species, described in three new genera: Palaeoichneumon freja gen. et sp. nov., P. ornatus sp. nov., P. danu sp. nov., P. micron sp. nov., P. mirabilis sp. nov., P. tenebrosus sp. nov., P. townesi sp. nov., Rudimentifera mora gen. et sp. nov., R. suspecta sp. nov., Dischysma maculata gen. et sp. nov., D. similis sp. nov., and D. ramulata sp. nov.     

A new nanhsiungchelyid turtle from the Late Cretaceous of Neixiang,Henan Province,China

A new genus and species of Nanhsiungchelyidae (Testudines: Cryptodira), Yuchelys nanyangensis n. g. n. sp., are described on the basis of a partial skeleton from the Late Cretaceous Gaogou Formation of Neixiang, Nanyang Basin, Henan Province. It is the first nanhsiungchelyid record in the east-central part of China and fills the geographical gap between the western (Uzbekistan, Mongolia, Northern and Southern China) and eastern (Japan) distribution areas of the family Nanhsiungchelyidae.     

A second hadrosauroid dinosaur from the early Late Cretaceous of Zuoyun,Shanxi Province,China

A second basal hadrosauroid dinosaur, Zuoyunlong huangi gen. et sp. nov., is reported from the early Late Cretaceous Zhumapu Formation in Zuoyun County, Shanxi Province, northern China. Zuoyunlong preserves a partial right ilium and ischium and is unique in having a very short postacetabular process 50% as long as the iliac central plate. Our cladistic analysis recovers Zuoyunlong as the most basal Late Cretaceous hadrosauroid, with a sister taxon relationship with Probactrosaurus from the late Early Cretaceous of Inner Mongolia. Including Zuoyunlong, four Cenomanian basal hadrosauroids have been recorded, and the two taxa in North America (Eolambia and Protohadros) represent the earliest known hadrosauroids outside of Asia. In the light of the proposed phylogenetic topology and biogeographic data, the discovery of Zuoyunlong indicates that the first dispersal of hadrosauroids from Asia to North America probably happened around the boundary between the Early and Late Cretaceous.     

New jewel beetles (Coleoptera: Buprestidae) and similar beetles from the Cretaceous and Early Paleogene of Asia

A new genus and two new species of jewel beetles are described, Andakhudukia ponomarenkoi gen. et sp. nov. from the Lower Cretaceous of Mongolia and Metabuprestium ustkivdense sp. nov. from the lowermost Paleogene of the Amur Region. In addition, four new monotypic genera that share some features with jewel beetles are described: Cretoelaterium kazanovense gen. et sp. nov. from the Lower Cretaceous of Eastern Transbaikalia and Cretopoena gratshevi gen. et sp. nov. from the Lower Cretaceous of Mongolia have been referred to the families Elateridae and Eucnemidae; Cretofalselaterium baiankhongoricum gen. et sp. nov. from the Lower Cretaceous of Mongolia and Cretogermen turonicum gen. et sp. nov. from the Upper Cretaceous of Kazakhstan have been erected for isolated elytra and placed in Coleoptera incertae sedis.