An enigmatic Ephedra-like fossil lacking micropylar tube from the Lower Cretaceous Yixian Formation of Liaoning,China

Angiosperms and gymnosperms are two well-separated groups in seed plants according to the current understanding. The huge gap between these two groups constitutes a serious threat against the Darwinism, which expects a continuous transitional series between them. The Lower Cretaceous Yixian Formation of Liaoning, China is famous for its megafossil angiosperms, including some early angiosperms and putative gnetalean plants. Here we document another Ephedra-like fossil plant, Pseudoephedra n. gen. n. sp., from the Yixian Formation on the basis of light microscopic (LM) and scanning electron microscopic (SEM) observations. Although its general morphology demonstrates a great resemblance to Ephedra, the expected micropylar tube characteristic of Ephedra is missing in Pseudoephedra. Instead a solid projection is seen on the top of the female parts. Such a puzzling character combination makes Pseudoephedra perplexing in seed plant phylogeny. If put in Ephedraceae (Gnetales), Pseudoephedra would destroy the only synapomorphy (micropylar tube) of the BEG clade. If put in angiosperms, Pseudoephedra would bridge the formerly huge gap between gymnosperms and angiosperms. Apparently, further investigation is needed to clarify the uncertain position of Pseudoephedra.     

Evolutionary consequences of dating the Yixian Formation

The Yixian Formation of northeastern China has yielded important new fossils that are fuelling debates on the origin of angiosperms, on the early radiation of birds and of mammals, and on the origin of feathers. Although these fossils provide a wealth of detailed anatomical information, knowledge of the absolute age of the Yixian Formation is crucial if we are to understand their true evolutionary significance. The age of the Yixian Formation has been disputed, but recent evidence provides strong support for an Early Cretaceous rather than a Late Jurassic age.     

New material of Xyelydidae (Hymenoptera) from the Lower Cretaceous Yixian Formation of China

Chifengilyda robusta, a new extinct sawfly genus and new species assigned to Xyelidae, is described and figured here based on one fossil specimen from the Lower Cretaceous Yixian Formation of Ningcheng in Inner Mongolia, China. Chifengilyda robusta n. gen. n. sp. differs from other xyelydids in having a forewing with pterostigma completely sclerotized, Sc closer to C, Sc1 about 3 times as long as Sc2, Sc1 intersecting C far beyond Rs base, 2r-m postfurcal and cell 1mcu relatively large. This new taxon further enriches the diversity of Xyelydidae in the Early Cretaceous, and even enhances our understanding of the evolution and inter-genera and interspecies relationships of this family.     

The Earliest Normal Flower from Liaoning Province, China

The early evolution of angiosperms has been a focus of intensive research for more than a century. The Yixian Formation in western Liaoning yields one of the earliest angiosperm macrofloras. Despite multitudes of angiosperm fossils uncovered, including Archaefructus and Sinocarpus , no bona fide normal flower has been dated to 125 Ma (mega-annum) or older. Here we report Callianthus dilae gen. et sp. nov. from the Yixian Formation (Early Cretaceous) in western Liaoning, China as the earliest normal flower known to date. The flower demonstrates a typical floral organization, including tepals, androecium, and gynoecium. The tepals are spatulate with parallel veins. The stamens have a slender filament, a globular anther, bristles at the anther apex, and in situ round-triangular pollen grains. The gynoecium is composed of two stylate carpels enclosed in a fleshy envelope, and develops into a "hip" when mature. Since the well-accepted history of angiosperms is not much longer than 125 Ma, Callianthus together with Chaoyangia, Archaefructus and Sinocarpus from the Yixian Formation demonstrate a surprisingly high diversity of angiosperms, implying a history of angiosperms much longer than currently accepted.     

High-precision Ar/Ar age for the Jehol Biota

Abundant fossils of the terrestrial Jehol Biota, including plants, insects, dinosaurs, birds, mammals and freshwater invertebrates, were discovered from the Yixian Formation and the overlying Jiufotang Formation in Inner Mongolia, Hebei Province and Liaoning Province, northeastern China. Because of the exceptional preservation of fossils, the Jehol Biota is one of the most important Mesozoic lagerstätten and is referred to as a “Mesozoic Pompeii”. The Jehol Biota has provided a rare opportunity to address questions about the origin of birds, the evolution of feathers and flight, the early diversification of angiosperms and the timing of placental mammal radiation. Six tuff samples and two basalt samples collected from the Tuchengzi, the Yixian and the Jiufotang formations near the classic outcrops in western Liaoning, NE China yielded high-precision ⁴⁰Ar/³⁹Ar ages. We obtain an age of 129.7 ± 0.5 Ma for a basaltic lava from the bottom of the Yixian Formation and an age of 122.1 ± 0.3 Ma for a tuff from the lowermost part of the overlying Jiufotang Formation. Our age results provide an age calibration of the whole Yixian Formation and show that the whole formation was deposited entirely within Early Cretaceous time over an interval of ~ 7 Ma.     

A new odonatan (Stenophlebiidae) from the Lower Cretaceous Sinuiju Formation of North Phyongan Province,the Democratic People’s Republic of Korea

A new fossil species, Stenophlebia ryonsangensis n. sp. (Stenophlebiidae), collected from the Lower Cretaceous non-marine Sinuiju Formation, North Phyongan Province, has the following forewing characters: preserved wing slender and longer than 47.1 mm; Cr long, with three cells below it, and well aligned with distal part of ScP; Sn shorter than Cr, one cell long; supplementary veinlet below Sn aligned with RP2 and about two cells long; base of IR1 five cells distal of base of RP2. This well preserved material is the first odonatan reported in the DPRK. Congeneric species has previously been found in the Lower Cretaceous Yixian Formation of western Liaoning Province, Northeast China, thus the new discovery of Stenophlebia ryonsangensis n. sp. may contribute to evaluating the distribution and migration of Stenophlebidae and may further indicate the close relationship of the fossil layer with the famous Jehol Biota in Northeast China.     

辽西义县下白垩统沙海组木化石新材料*

辽西地区下白垩统沙海组是我国北方地区重要的白垩纪木化石产出层位,其产出的木化石数量丰富、类型多样.尽管前人开展了部分研究,但目前对沙海组木化石植物群组成特征的认识仍相对薄弱.本文报道了辽西义县上石洞沟地区沙海组产出的木化石新材料,共鉴定出2属3种,分别为:Phyllocladoxylon cf.eboracense(Holden)Kr?usel、Xenoxylon conchylianum Fliche 及 X.watarianum Nishida and Nishida.此发现丰富了对沙海组木化石多样性特征的认识,为揭示辽西地区早白垩世晚期的森林组成特征提供了新的化石证据.本文总结了辽西地区早白垩世木化石的多样性特征,从木化石的角度推断辽西地区在早白垩世中晚期森林植被面貌可能发生了一定程度的更替.此外,本文对比了辽西地区侏罗纪及白垩纪异木属木化石种级多样性,认为该属在辽西地区晚中生代一直是优势类群,但种级组成上差异明显.     

A new Mesozoic Chinese genus of aeshnopteran dragonflies (Odonata: Anisoptera: Progobiaeshnidae)

Mongoliaeshna sinica gen. et sp. n., third record of the Mesozoic aeshnopteran family Progobiaeshnidae is described from the Lower Cretaceous of Yixian Formation in Liutiaogou (Ningcheng County, Inner Mongolia, China).     

辽西早白垩世义县组Ruffordia和Nageiopsis的发现及其地层意义

报道辽西义县组两种颇具地层意义的植物化石。Ruffordia goeppertii(Dunker)Seward和Nageiopsis exgr.samioides(Fontaine)berry,根据植物化石认为义县组的时代应属于早白垩世。     

Discovery of the Jehol Biota from the Celaomiao region and discussion of the Lower Cretaceous of the Bayingebi Basin,northwestern China

Some typical components of the Jehol Biota, including conchostracans Eosestheria sp., the mayfly Ephemeropsis trisetalis Eichwald, 1864, the aquatic beetle Coptoclava longipoda Ping, 1928, and a fragmentary dragonfly, are reported for the first time from the Bayingebi Formation in the Celaomiao region, western Inner Mongolia, China. This discovery indicates that the middle Upper Member of Bayingebi Formation can be correlated with the upper Yixian and the lower Jiufotang formations in western Liaoning Province. Combining it with the radio-isotopic dating result, we further believed that the Upper Member of Bayingebi Formation could be roughly correlated with the Yixian, Jiufotang, and Shahai formations, and the overlying Suhongtu Formation with the Fuxin Formation in western Liaoning Province.In the major Bayingebi Basin, palaeontological and radio-isotopic dating evidence shows that the Bayingebi Formation has a long depositional history of over 30 Ma: its Upper Member bearing the Jehol Biota and the early Fuxin Biota is probably coeval to the Yixian, Jiufotang and Shahai formations and has a Barremian–early Albian age; its Lower Member may be Berriasian–Hauterivian in age and could be correlated with the upper Tuchengzi, Zhangjiakou, and Dabeigou formations in northern Hebei Province. This suggests that the Bayingebi Formation should be promoted to the stratigraphic rank of group and subdivided into several secondary units (formations). Unlike the previous result, the Yingen Formation is considered across the Lower Cretaceous–Upper Cretaceous boundary and being late Albian–early Turonian in age.     

A basal oxyteline rove beetle (Coleoptera: Staphylinidae) from the Early Cretaceous of China: Oldest record for the tribe Euphaniini

A remarkable new rove beetle, Protodeleaster glaber gen. et sp. nov, is described and illustrated based on two well-preserved specimens from the Lower Cretaceous Yixian Formation of Liaoning Province, China. The new genus is placed in the extant staphylinid subfamily Oxytelinae, and recent tribe Euphaniini, based on several characteristic features (e.g. a single pair of wide paratergites on abdominal segments; open procoxal fissures; contiguous mesocoxae; abdominal sternite II short and poorly sclerotized). This find from the Early Cretaceous documents the oldest fossil representative of the tribe Euphaniini. Morphologically, it resembles most closely the recent genus Platydeleaster Schülke, 2003, an unusual member of the extant Oxytelinae. According to the currently accepted hypothesis of the phylogenetic position of Euphaniini and the prior discovery of other taxa from the Late Jurassic, we suggest the tribe might have first appeared at least as early as the Late Jurassic.     

吉林汪清早白垩世似卷柏化石*

文中描述了发现于吉林汪清下白垩统大拉子组似卷柏化石:纤细草本,侧叶和中叶呈四行排列。侧叶互生,卵形,全缘,顶端尖锐,叶片前端略向内侧弯曲,叶背呈龙骨状,基部无柄,略呈鞘状;中叶生于两侧叶之间,形态与侧叶相似,在茎上密集贴生。该化石与报道自我国辽西下白垩统义县组下部尖山沟层的多产似卷柏Selaginellites fausta(Wu)Sun and Zheng特征相似,但由于未保存生殖器官结构,无法进一步详细对比,因此将其定为Selaginellites cf.fausta(Wu)Sun and Zheng。这是我国目前为止发现的距今最近的似卷柏化石,丰富了中国似卷柏的化石记录。     

Nuurcala obesa sp. n. (Blattida,Caloblattinidae) from the Lower Cretaceous Yixian Formation in?Liaoning?Province,China

Nuurcala obesa sp. n., in the cockroach family Caloblattinidae, is described from the Lower Cretaceous Yixian Formation (Liaoning Province, China) based on a combination of differential characters of fore- and hind wing venation, colouration and body structures. Systematically, Nuurcala (Vršanský, 2003), known from the Cretaceous sediments of Bon Tsagaan and Khurilt, Mongolia, is closely related to other genera of Caloblattinidae known from the Jurassic and Cretaceous localities in other parts of Asia.     

A two-headed reptile from the Cretaceous of China

A malformed embryonic or neonate choristoderan reptile from the Lower Cretaceous Yixian Formation of northeastern China is described. The tiny skeleton exhibits two heads and two necks, with bifurcation at the level of the pectoral girdle. In a fossil, this is the first occurrence of the malformation known as axial bifurcation, which is well known in living reptiles.     

辽宁西部晚中生代地层研究之进展及存在问题——辽宁西部晚中生代地层和鱼群研究之四

辽宁西部晚中生代地层的综合层序为:义县组、九佛堂组、沙海组/张老公屯组、阜新组和孙家湾组.中西部朝阳—喀左—建昌以及凌源—三十家子盆地的义县组大致相当于东部阜新—义县—锦州盆地的狭义义县组及其底部的北票尖山含化石沉积夹层;中西部的九佛堂组则可与东部的金刚山、吐呼鲁和九佛堂三个岩组相对比;张老公屯组火山岩在层序上大部分可能位于九佛堂组和阜新组之间.以北票鲟、中华弓鳍鱼和狼鳍鱼为代表的鱼类化石普遍见于中国北方热河群及其相当岩群的下部河湖相地层中,以粒鳞鱼、固阳鱼和副狼鳍鱼为代表的鱼类化石多见于上部的扇三角洲和湖沼相含煤地层中.热河群及相当岩群时代的确定以及陆相侏罗—白垩系界线的厘定受制于目前地层和生物化石的研究程度.从鱼群的面貌看,义县—九佛堂组、沙海—阜新组及相当地层的时代可能分别为晚侏罗世晚期—早白垩世早期和早白垩世中期.     

A sauropod rib with an embedded theropod tooth: direct evidence for feeding behaviour in the Jehol group,China

Xing, L, Bell, P.R., Currie, P.J., Shibata, M., Tseng, K. & Dong, Z. 2012: A sauropod rib with an embedded theropod tooth: direct evidence for feeding behaviour in the Jehol group, China. Lethaia, Vol. 45, pp. 500–506. A fragmentary rib from the Lower Cretaceous (Barremian) Yixian Formation in northeastern China preserves rare, direct evidence of feeding behaviour by an unidentified theropod. The rib, which comes from the holotype of Dongbetitan, preserves an embedded, broken theropod tooth. Comparison of the tooth with all known theropods from the Yixian Formation suggests that it belongs to a new taxon of medium‐sized theropod. Given the large size difference between the sauropod and the theropod and the absence of reactive bone growth around the tooth, the bite likely occurred post‐mortem during scavenging. Recognition of a new, medium‐sized theropod increases the known diversity of taxa from the Yixian Formation and helps fill a gap in the theropod palaeoecology of that formation, which previously consisted of only small (<2 m) forms. □China, Cretaceous, feeding behaviour, theropod, titanosauriformes, sauropod.     

Phylogeny and evolution of Mesozoic and extant lineages of Histeridae (Coleoptera), with discovery of a new subfamily Antigracilinae from the Lower Cretaceous

In order to place a newly discovered species Antigracilus costatus gen. sp. n. from the Lower Cretaceous Yixian Formation (China) and to assess previously unplaced fossil taxa, we investigated the relationships of extant and extinct lineages of Histeridae based on three data sets: (i) 69 morphological characters belonging to 48 taxa (representing all 11 subfamilies and 15 of 17 tribes of modern Histeridae); (ii) partitioned alignment of 6030 bp from downloaded nucleotide sequences (28S, CAD, COI, 18S) of 50 taxa (representing 10 subfamilies and 15 of 17 tribes of modern Histeridae); and (iii) a combined morphological and molecular dataset for 75 taxa. Phylogenetic analyses of the morphology and combined matrices recovered the new Lower Cretaceous taxon as a sister group to remaining Histeridae and it is placed in †Antigracilinae subfam. n. †Antigracilinae constitutes the earliest record of Histeridae from the Lower Cretaceous Yixian Formation (∼125 Myr), backdating the minimum age of the family by 25 Myr from the earliest Cenomanian (~99 Myr) to the Barremian of the Cretaceous Period. Our molecular phylogeny supports Histeridae to be divided into seven different clades, with currently recognised subfamilies Abraeinae (sensu lato), Saprininae, Chlamydopsinae, and Histerinae (sensu lato) recovered as monophyletic, while Dendrophilinae, Onthophilinae, and Tribalinae are polyphyletic taxa. The Burmese amber species †Pantostictus burmanicus Poinar & Brown is placed as a sister group to the tribe Plegaderini (Abraeinae) and was assigned as a new tribe Pantostictini trib. n. Both molecular and combined phylogenies recovered the subfamilies Trypanaeinae and Trypeticinae deeply within the subfamily Abraeinae (sensu lato), and they are downgraded into Trypanaeini stat. n. and Trypeticini stat. n.     

A new,well-preserved genus and species of fossil Glaphyridae (Coleoptera,Scarabaeoidea) from the Mesozoic Yixian Formation of Inner Mongolia,China

A new genus and species of fossil Glaphyridae, Cretohypna cristata gen. et sp. n., is described and illustrated from the Mesozoic Yixian Formation. This new genus is characterized by the large body; large and strong mandibles; short labrum; elytra without longitudinal carina; and male meso- and possible metatibia apically modified. A list of described fossil glaphyrids of the world is provided. This significant finding broadens the known diversity of Glaphyridae in the Mesozoic China.     

Morphology and affinities of an Early Cretaceous Ephedra (Ephedraceae) from China

Detailed investigations on Lower Cretaceous Ephedra L. fossils (Gnetopsida) reveal morphological characters similar to those of extant Ephedra rhytidosperma Pachomova, including articulate branches with many fine longitudinal striations, a dichasial branching pattern, uni- or bi-ovulate cones with paired bracts, cones terminal on branchlets, and seeds with a short, straight micropylar tubes, covered by numerous regular and prominent transverse laminar protuberances. Fossils are similar to extant E. rhytidosperma reproductive organs but differ in some vegetative structures and are described and discussed here as Ephedra archaeorhytidosperma Y. Yang et al. Because E. rhytidosperma is currently considered one of the most specialized members in Ephedra L. section Pseudobaccatae Stapf, the occurrence of E. archaeorhytidosperma in the Yixian Formation suggests that Ephedra L. was perhaps a more diverse genus in the Lower Cretaceous. Perhaps the evolution and diversity of Ephedra L. was already in place by the Lower Cretaceous and certainly before the end of the Mesozoic.