Daohugou Research Articles

A new structurally preserved fern rhizome of Osmundaceae (Filicales) Ashicaulis wangii sp. nov. from the Jurassic of western Liaoning and its significances for palaeobiogeography and evolution

Permineralized osmundaceous rhizome with anatomical and phylogenetic information plays a significant role in understanding the origin, evolution, and diversity variation of the fern family Osmundaceae in geological history. The northern Hebei and western Liaoning region is one of the most important fossil localities for the Jurassic osmundaceous rhizome fossils in the Northern Hemisphere; however, the diversity character of osmundaceous rhizome fossil remains poorly known. A new structurally preserved fern rhizome species, Ashicaulis wangii sp. nov., is described from the Middle Jurassic Tiaojishan Formation in Beipiao City, Liaoning Province, northeastern China. The rhizome is composed of heterogeneous pith, an ectophloic-dictyoxylic siphonostele, a two-layered cortex, and a mantle of adventitious roots and petiole bases. The xylem cylinder, with complete leaf gaps, consists of 15–17 xylem strands. The petiole base is characterized by a heterogeneous sclerotic ring and numerous sclerenchyma masses in the petiolar cortex. Among five known Ashicaulis species with heterogeneous sclerotic ring, four of them are documented from China. Therefore, osmundaceous rhizome fossils from China show endemic anatomical characteristics and significances for palaeobiogeography. Comparisons of anatomical features suggest that A. wangii sp. nov. bears close similarities to Osmunda pluma Miller from the Paleocene of Dakota, USA. Fossil species of A. wangii provides new evidence for further understanding the species diversity of osmundaceous rhizome fossil in China and in the Northern Hemisphere, and contributes to exploring the macroevolution process of the Mesozoic osmundaceous plants.

A specialized new species of Ashicaulis (Osmundaceae, Filicales) from the Jurassic of Liaoning, NE China

A new species of structurally preserved fern rhizome, Ashicaulis plumites (Osmundaceae, Filicales), is described from the Middle Jurassic Tiaojishan Formation in western Liaoning Province, NE China. The new species is characterized by a peculiar sclerenchyma mass in the petiolar vascular bundle concavity. This sclerenchyma mass varies from a linear-shape to a mushroom-like shape with a remarkable outward protuberance, which distinguishes the present new species from other Ashicaulis species. Such a protuberance is very rare among osmundaceous ferns, and should represent a unique type for sclerenchymatous tissue in the osmundaceous vascular bundle concavity. Recognition of the peculiar structure of this new fossil species enriches anatomical diversity of permineralized osmundaceous ferns, indicating that the family Osmundaceae might have experienced a remarkable diversification during the Middle Jurassic in NE China. The new species show anatomical similarities to Osmunda pluma Miller from the Palaeocene of North America. The occurrence of A. plumites in the Middle Jurassic of China provides a new clue for understanding the evolution of some members of the living subgenus Osmunda.

First rove beetles from the Jurassic Talbragar Fish Bed of Australia (Coleoptera, Staphylinidae)

The first two rove beetle fossils discovered from the Late Jurassic Talbragar Fish Bed in New South Wales, Australia are described and illustrated.Juroglypholoma talbragarensen. sp. is the second fossil record for one of the smallest and latest recognized staphylinid subfamily Glypholomatinae. The other staphylinid,Protachinus minorn. gen. n. sp., is an unusual member of extant subfamily Tachyporinae (tribe Tachyporini). It significantly retains several distinct features, including entire epistomal suture, and abdominal tergites III–VI each with a pair of basolateral ridges. The discovery of a new glypholomatine in Australia, together with recently reported one from the Middle Jurassic Daohugou biota of China, suggests the subfamily Glypholomatinae was probably much more widespread in the Jurassic than previously thought.

A Jurassic avialan dinosaur from China resolves the early phylogenetic history of birds

The recent discovery of small paravian theropod dinosaurs with well-preserved feathers in the Middle-Late Jurassic Tiaojishan Formation of Liaoning Province (northeastern China) has challenged the pivotal position of Archaeopteryx, regarded from its discovery to be the most basal bird. Removing Archaeopteryx from the base of Avialae to nest within Deinonychosauria implies that typical bird flight, powered by the forelimbs only, either evolved at least twice, or was subsequently lost or modified in some deinonychosaurians. Here we describe the complete skeleton of a new paravian from the Tiaojishan Formation of Liaoning Province, China. Including this new taxon in a comprehensive phylogenetic analysis for basal Paraves does the following: (1) it recovers it as the basal-most avialan; (2) it confirms the avialan status of Archaeopteryx; (3) it places Troodontidae as the sister-group to Avialae; (4) it supports a single origin of powered flight within Paraves; and (5) it implies that the early diversification of Paraves and Avialae took place in the Middle-Late Jurassic period.

Ashicaulis beipiaoensissp. nov., a New Osmundaceous Fern Species from the Middle Jurassic of Liaoning Province, Northeastern China

A new structurally preserved fern rhizome species, Ashicaulis beipiaoensis (Osmundaceae), is described from the Middle Jurassic Tiaojishan Formation in Beipiao City, Liaoning Province, northeastern China. The rhizome, with a maximum diameter of 4.0–4.5 cm, is composed of a homogeneous parenchymatous pith, an ectophloic-dictyoxylic siphonostele, a two-layered cortex, and a mantle of adventitious roots and petiole bases. The xylem cylinder consists of 13–16 xylem strands. The petiole base is characterized by a homogeneous sclerotic ring and a crescent-shaped sclerenchyma mass in the vascular bundle concavity. One large homogeneous sclerenchyma mass, accompanied by several smaller thick-walled fiber clusters, occurs in the petiolar stipular wings. Comparisons of anatomical features suggest that A. beipiaoensis sp. nov. shows distinct differences when compared to previously reported fossil and living osmundaceous taxa but bears close similarities to Osmunda shimokawaensis from the Middle Miocene of Hokkaido, Japan. The new species and O. shimokawaensis may represent an extinct branch in the Osmundaceae evolutionary tree. The fossil species of A. beipiaoensis provides further information for understanding the development and geological occurrences of osmundaceous rhizomes in the Northern Hemisphere.

40 Ar/ 39 Ar age constraints on the Haifanggou and Lanqi formations: When did the first flowers bloom?

Abstract Well-preserved Mesozoic terrestrial fossils were discovered in the Haifanggou Formation and the overlying Lanqi Formation (or their correlative strata) in NE China. The recent discoveries of Schmeissneria sinensis and Xingxueanthus sinensis from the middle and upper Jurassic Haifanggou Formation provide evidence that the origin of angiosperms could be predate the Early Cretaceous. In addition to the finding of pre-Cretaceous angiosperms from the Haifanggou Formation, the overlying Lanqi Formation yields a rich and varied terrestrial flora. The high diversity and abundance of the palaeoflora from these formations provide a unique window to understand floral evolution and its diversification in the Mesozoic. Two tuff samples and one andesite sample collected from the Haifanggou and Lanqi formations near Beipiao City, Liaoning, NE China yield robust 40 Ar/ 39 Ar age results. Our 40 Ar/ 39 Ar age of 166.7 ± 1.0 Ma for plagioclases from one tuff interbedded in the fossiliferous horizons of the middle Haifanggou Formation provides accurate age calibration for the pre-Cretaceous angiosperms for the first time. Moreover, our age results for these fossil-bearing formations will improve our knowledge of the Jurassic environment in general, including the link between plants and atmospheric CO 2 . Supplementary material: Details of analysis procedures, Ar isotopic data corrected for blanks, mass discrimination, radioactive decay and J values are available at: http://www.geolsoc.org.uk/SUP18575 .

Reduced plumage and flight ability of a new Jurassic paravian theropod from China

Feathered theropods were diverse in the Early Cretaceous Jehol Group of western Liaoning Province, China. Recently, anatomically distinct feathered taxa have been discovered in the older Middle-Late Jurassic Tiaojishan Formation in the same region. Phylogenetic hypotheses including these specimens have challenged the pivotal position of Archaeopteryx in bird phylogeny. Here we report a basal troodontid from the Tiaojishan Formation that resembles Anchiornis, also from Jianchang County (regarded as sister-taxa). The feathers of Eosinopteryx are less extensive on the limbs and tail than Anchiornis and other deinonychosaurians. With reduced plumage and short uncurved pedal claws, Eosinopteryx would have been able to run unimpeded (with large foot remiges cursorial locomotion was likely problematic for Anchiornis). Eosinopteryx increases the known diversity of small-bodied dinosaurs in the Jurassic, shows that taxa with similar body plans could occupy different niches in the same ecosystem and suggests a more complex picture for the origin of flight.

Snipe flies (Diptera: Rhagionidae) from the Daohugou Formation (Jurassic), Inner Mongolia, and the systematic position of related records in China

Abstract: Four new species referred to three new genera and one known genus of fossil snipe flies (Family Rhagionidae) from the Daohugou Formation of Chifeng City in Inner Mongolia, north‐eastern China, are described as Daohugorhagio elongatus gen. et sp. nov., Parachrysopilus jurassicus gen. et sp. nov., Sinorhagio sinuatus sp. nov. and Trichorhagio gregarius gen. et sp. nov. These taxa represent only a fraction of the rhagionid assemblage in the Daohugou biota. They contribute towards the high diversity and abundance of snipe flies during the latest Middle Jurassic – earliest Late Jurassic. The diagnosis of Sinorhagio K. Zhang, Yang and Ren, 2006 is revised based on the new results. Many genera and species from the Lower Cretaceous of China have been assigned to Rhagionidae. Most of these do not actually belong to this family: specifically Mesorhagiophryne incerta Hong and Wang, 1990, M. robusta Hong and Wang, 1990, Mesostratiomyia laiyangensis Hong and Wang, 1990, Stratiomyopsis robusta Hong and Wang, 1990, Longhuaia orientalis Hong, Wang and Sun, 1992, Basilorhagio venusius Ren, 1995. Pauromyia oresbia Ren, 1998 is transferred to an archisargid genus as Sharasargus oresbius (Ren, 1998) comb. nov.

Stratigraphy and Geochronology of Vertebrate Fossil‐Bearing Jurassic Strata from Linglongta, Jianchang County, Western Liaoning, Northeastern China

Abstract:Northeastern China contains widely distributed Jurassic terrestrial strata that have yielded many spectacular mammal and pterosaur fossils, in addition to feathered dinosaur fossils and more recent discoveries from Jianchang, particularly from western Liaoning. However, the fossil‐bearing stratigraphic succession, regional correlation, and age estimates of the fossils found in Jianchang County and nearby areas have been contentious. Here, we report on the vertebrate fossil‐bearing Jurassic stratigraphy from Linglongta, Jianchang County, western Liaoning, including a SHRIMP U‐Pb zircon date unambiguously associated with the fossil horizons. The primary goal was to determine the vertebrate fossil‐bearing succession. A further aim was to provide age estimations for the fossil‐bearing horizon as well as the earliest appearance of feathered dinosaurs, the eutherian–placental clade, and transitional pterosaurs. Field investigations showed that the vertebrate fossil‐bearing stratigraphic succession in Jianchang County mainly consists of basal andesites overlain by rhythmic tuffs and tuffaceous lacustrine sediments, with the upper intermediate or acidic lavas interbedded with laminated more or less tuffaceous lacustrine deposits. This sequence correlates well with the Middle Jurassic Lanqi/Tiaojishan Formation in northeastern China. Detailed and accurate field observations showed that the well‐preserved vertebrate fossils were buried in either the middle or the upper fine‐grained laminated lacustrine deposits. Previous and current SHRIMP U‐Pb zircon dates provide an age estimation of 161–159 Myr for the fossil‐bearing horizon and vertebrates. This indicates that the earliest appearance of feathered dinosaurs here was more than 159 Myr ago and unquestionably older than Archaeopteryx from Germany, making these the earliest known feathered dinosaurs in the world. Furthermore, the eutherian–placental clade and the known transitional pterosaurs first emerged no later than 161 Myr. The vertebrate assemblage unearthed recently from Linglongta and neighboring areas in Jianchang County belongs to the Daohugou Biota. In addition to feathered dinosaurs, this biota was characterized by mammals, primitive pterosaurs, insects, and plants and was present in Inner Mongolia, western Liaoning, and northern Hebei in northeastern China during the Middle–Late Jurassic.

A New Chinese Anurognathid Pterosaur and the Evolution of Pterosaurian Tail Lengths

Abstract:A new anurognathid pterosaur specimen from the Middle Jurassic Tiaojishan Formation of Qinglong, northern Hebie Province is described. The new specimen is referred to Dendrorhynchoides, based on the general morphology of the skeleton, but it represents a new species, named here as Dendrorhynchoides mutoudengensis sp. nov.. It is characterized by the presence of short, robust and straight teeth, and bearing wing metacarpal approximately 40% of the length of humerus. The new specimen provides further osteological information for anurognathid pterosaurs, especially the presence of a relatively elongate tail.

New Jurassic Cercopoidea from China and their evolutionary significance (Insecta: Hemiptera)

Abstract: A new family, Sinoalidae Wang and Szwedo fam. nov., is described from the Middle Jurassic Daohugou Biota (Inner Mongolia, China). Two new genera with three new species (Sinoala parallelivena Wang and Szwedo gen. et sp. nov., Jiania crebra Wang and Szwedo gen. et sp. nov., and Jiania gracila Wang and Szwedo sp. nov.) are erected based on well‐preserved whole‐bodied specimens. The morphological characters of Procercopidae and the new family are given, and a key to the species of Sinoalidae is presented. The genera Luanpingia Hong, 1983 and Huabeicercopis Hong, 1983 are revised and attributed to Sinoalidae. The genera Mesocercopis Hong, 1983 and Sinotettegarcta Hong, 1986 are considered junior synonyms of Anthoscytina Hong, 1983. Taxa assigned to Sinoalidae fam. nov. cannot be attributed to any previously known family, but share some general (plesiomorphic) characters with ancient Clypeata, for example, postclypeus distinctly swollen, transversely wrinkled, antenna with a flagellum of a few elongate segments, frons with median ocellus and lateral ocelli on crown. Moreover, the new family is closely related to Procercopidae (Cercopoidea) based on a pronotum with a median incision at the hind margin; tegmen slender, partly punctuate, basal portion of Sc not exceeding apex of basal cell, and hind legs with lateral spines. It has a mixture of ancestral characters shared with Hylicelloidea and Jurassic Procercopidae and some derived characters. Therefore, it is tentatively placed in Cercopoidea. A preliminary phylogram of Clypeata is presented based on the combination of fossil and morphological data.

Distinct but rare archisargid flies from Jurassic of China (Diptera, Brachycera, Archisargidae) with discussion of the systematic position of Origoasilus pingquanensis Zhang et al., 2011

Three new archisargid species referred to one new genus, Flagellisargus sinicus, F. venustus and F. robustus, are described based on three impressions from the Callovian–Oxfordian of the “Daohugou Formation” in Daohugou, Chifeng, Inner Mongolia, China. The presence of an elongated flagellum and large male genitalia places these new findings with the distinct but rare archisargid flies. The systematic position of Origoasilus pingquanensis Zhang et al., 2011 is reassessed, placing it with Archisargidae within Archisargoidea rather than Asiloidea. The Origoasilidae is a junior synonym for Archisargidae.

Glypholomatine Rove Beetles (Coleoptera: Staphylinidae): a Southern Hemisphere Recent Group Recorded from the Middle Jurassic of China

A new fossil rove beetle, Juroglypholoma antiquum n. gen. n. sp., is described and figured based on a well-preserved specimen from the Middle Jurassic Daohugou biota (ca. 165 Ma), Inner Mongolia, northeastern China. It represents the first fossil belonging to one of the smallest and latest recognized staphylinid subfamilies, Glypholomatinae, which is now endemic to the Southern Hemisphere. The new genus is assigned to Glypholomatinae based on its body shape and size, clubbed antennae, relatively long elytra, abdominal intersegmental membranes with brick-wall-like pattern, metacoxae slightly excavate to receive the short metafemora, and paired curved ridges in the anterolateral margins of sternites IV–VI. It can be easily separated from the extant genera Glypholoma and Proglypholoma by a combination of shorter elytra with apical four abdominal segments exposed; and antennomeres 1 and 2 normal, not dilated, apical three antennomeres forming a slight club. The first discovery of a new species from the Middle Jurassic of China illustrates the antiquity of Glypholomatinae, and indicates that the Omaliine group of subfamilies had already originated by the Middle Jurassic.

Late Jurassic salamandroid from western Liaoning, China.

A Jurassic salamander, Beiyanerpeton jianpingensis (gen. et sp. nov.), from a recently found site in western Liaoning Province, China is the earliest known record of Salamandroidea. As a Late Jurassic record of the group, it extends the range of the clade by ~40 Ma. The Late Jurassic taxon is neotenic and represented by exceptionally preserved specimens, including fully articulated cranial and postcranial skeletons and bony gill structures close to the cheek region. The fossil beds, consisting of dark-brown volcanic ash shales of the Upper Jurassic Tiaojishan (Lanqi) Formation (Oxfordian), underlie trachyandesite rocks that have yielded a SHRIMP zircon U-Pb date of 157 ± 3 Ma. The fossiliferous beds are substantially older than the Jehol Group, including the Yixian Formation ((40)Ar/(39)Ar dates of 122-129 Ma), but slightly younger than the Middle Jurassic Daohugou horizon ((40)Ar/(39)Ar date of 164 ± 4 Ma). The early fossil taxon shares with extant salamandroids derived character states, including: separated nasals lacking a midline contact, angular fused to the prearticular in the lower jaw, and double-headed ribs on the presacral vertebrae. In contrast to extant salamandroids, however, the salamander shows a discrete and tooth-bearing palatine, and unequivocally nonpedicellate and monocuspid marginal teeth in large and presumably mature individuals. The finding provides insights into the evolution of key characters of salamanders, and also provides direct evidence supporting the hypothesis that the split between Cryptobranchoidea and Salamandroidea had taken placed before the Late Jurassic Oxfordian time. In this aspect, both paleontological and molecular data now come to agree.

New taxa of snipe flies (Diptera: Brachycera: Rhagionidae) in the Daohugou Biota, China

Three impressions of snipe flies from the uppermost Middle Jurassic or lowermost Upper Jurassic Daohugou Formation in northeastern China are described as Protorhagio parvus sp. nov. and Lithorhagio megalocephalus get. et sp. nov. Protorhagio parvus is the first record of the genus Protorhagio Rohdendorf, 1938 outside the Karatau-Mikhailovka locality (Kazakhstan), which has implications for biostratigraphic correlation of the formations, in which they are found. The taxonomic position of Lithorhagio gen. nov. is discussed. Although Orsobrachyceron Ren, 1998 demonstrates some resemblance in form to the new genus, it probably belongs to Xylomyidae rather than Rhagionidae.

Timing of the earliest known feathered dinosaurs and transitional pterosaurs older than the Jehol Biota

The Early Cretaceous Jehol Biota in China has produced numerous well preserved fossils of feathered theropods and early birds. Recent discoveries of feathered dinosaurs, as well as transitional pterosaurs and a sexually mature individual of Darwinopterus preserved together with an egg from the Daohugou Biota of an earlier age than the Jehol Biota, in northeastern China, have greatly enriched our knowledge of the transition from dinosaurs to birds and primitive to derived pterosaurs. The age estimate of fossils or host strata, however, has proven to be contentious and varies widely from the Middle Jurassic to the Early Cretaceous. Here, we report a SHRIMP U–Pb zircon date unambiguously associated with the fossil horizons, and thus, for the first time, provide an age calibration for the earliest appearance of feathered dinosaurs and transitional pterosaurs. Date results indicate that the feathered dinosaurs of China were present more than 161Ma ago, unquestionably older than Archaeopteryx in Germany, and are the earliest known feathered dinosaurs in the world. Furthermore, feathers appeared in ornithischians before 159Ma rather than late in the Early Cretaceous. The known transitional pterosaurs first emerged before 161Ma. The Daohugou Biota, containing mammals, primitive pterosaurs, insects and plants, in addition to the feathered dinosaurs, was living in Inner Mongolia ,western Liaoning and northern Hebei in northeastern China during the Middle Jurassic.

A new rhamphorhynchid (Pterosauria: Rhamphorhynchidae) from the Middle/Upper Jurassic of Qinglong, Hebei Province, China

A heavily compressed, but nearly complete fossil skeleton recovered from the Middle/Upper Jurassic Tiaojishan Forma-tion of Mutoudeng, Qinglong County, Hebei Province, China, represents a new genus and species of long-tailed pterosaur,Qinglongopterus guoi gen. et sp. nov. The holotype and only known specimen has an estimated forelimb length of 0.18m. The new taxon is distinguished by a relatively short skull, a remarkably short pteroid with a distinctive knob-like distalexpansion, and a prepubis with a relatively slender distal process. Phylogenetic analysis demonstrates that Qinglongopter-us is a member of Rhamphorhynchidae, exhibiting many of the unique character states found in members of this clade.Qinglongopterus is strikingly similar to Rhamphorhynchus and more closely related to this taxon than to any other rham-phorhynchine, this pairing is supported by morphometric data and several synapomorphies (short, broad nasal process ofthe maxilla; forelimb length more than four times that of the hind limb; wing-phalanx one more than twice the length ofthe tibia). Qinglongopterus demonstrates that the highly derived skeletal morphology of Rhamphorhynchus, known onlyfrom the latest Jurassic (Tithonian) of Europe, had already appeared by the start of the Late Jurassic. This hints at evolu-tionary stasis in Rhamphorhynchinae, a phenomenon seemingly also present in two other clades of basal pterosaurs,Anurognathidae and Scaphognathinae, and contrasting sharply with basal monofenestratans which appear to have undergone extensive evolutionary change during the same interval.

QG2井熔结火山碎屑岩锆石定年及其地质意义<br>U-Pb Zircon Dating of the Mesozoic Welded Pyroclastics in the QG2 Well and Its Geological Significance

辽河坳陷西部凹陷齐家潜山的Qg2井钻遇一套含油性较好的火山岩，通过岩石学和地球化学特征研究，认为是一套典型的壳源酸性钙性岩类，确定为爆发相的熔结角砾凝灰岩。该套火山岩形成时代和地层归属一直存在较大分歧，当时根据区域资料将其归为中生界早白垩纪义县组，但缺乏精确的年代学证据。为了进一步确定该套火山岩的形成时代和地层层位，笔者先是利用LA-ICP-MS锆石原位U-Pb定年方法，获得了熔结角砾凝灰岩的喷发年龄为168.9 ± 1.1 Ma，喷发时代为中生代中侏罗世，与辽西建昌盆地、河北承德盆地以及北京西山马兰村的的髫髻山组的火山岩在形成时代和岩性特征上具有可比性，因此，该套火山岩地层层位确定为髫髻山组，修正了以往对该套火山岩地层归属的观点，为下一步研究该类火山岩油气藏的空间展布奠定了基础。 The QG2 Well drilled into a suite of volcanic rocks with good oil-bearing property, which is located in Qijia buried hill, the western sag of Xialiaohe Concave. According to the results of petrography and geochemistry, this suite of volcanic rocks is identified as a suit of classical acid calcareous rock of crust source type, a lava tuff breccia with explosive faces. However, there has been a long debate on the formation age and stratum layer of this suite of volcanic rocks. Based on the regional geological data, it is previously classified into Yixian Formation of Early Cretaceous, but lack of precise chronological evidence. In order to accurately determine its formation age and stratum layer, we performed LA-ICP-MS. Our results indicated that this suite of volcanic rocks was formed at 168.9 ± 1.1 Ma in the period of Middle Jurassic, which is comparable to Tiaojishan Formation in Jianchang Basin of Western Liaoning Province, Chende Basin of Hebei Province, Malan Village of Western Hills of Beijing. So its stratum was defined as Tiaojishan Formation. The result revised the stratigraphical division of this suite of volcanic rocks. This opens the door for further study the distribution of oil and gas in this type of volcanic rocks.

Trichomes on the leaves of Anomozamites villosus sp. nov. (Bennettitales) from the Daohugou beds (Middle Jurassic), Inner Mongolia, China: Mechanical defence against herbivorous arthropods

The abaxial leaf surfaces of Anomozamites villosus sp. nov., a new species of bennettitalean foliage from the Middle Jurassic Daohugou beds of Inner Mongolia, China, are covered with soft, shaggy hairs that are loosely, but regularly distributed across the lamina. Selectively arranged, long, stiff or acerate hairs directed or bent towards the leaf apex, project on the abaxial side of the leaf from the rachis margins. Both types of hairs are interpreted predominantly as adaptations for passive defence against damage by arthropods (sap-sucking, leaf-chewing or oviposition) rather than being morphological responses to physical environmental parameters, e.g. xeromorphic features. As several of the leaves show evidence for high levels of leaf-margin feeding by phytophagous arthropods, these mechanisms have not been entirely effective and may have evolved to defend against only selected arthropods or behavioural strategies. These findings contribute to the reconstruction of ecological interactions in the exceptionally preserved Jurassic Daohugou biota of northern China, and provide a rare insight into the plant–arthropod co-evolutionary ‘arms race’.

Two new species of Palaeoarthroteles Kovalev and Mostovski (Diptera, Rhagionidae) from the Callovian-Oxfordian (Jurassic) Daohugou biota of China

Two new species of fossil snipe flies (Rhagionidae) from the Daohugou Formation of Chifeng City in Inner Mongolia Autonomous Region (northeastern China) are described as Palaeoarthroteles jurassicus nov. sp. and P. pallidius nov. sp. They are the first record of the genus Palaeoarthroteles Kovalev and Mostovski beyond Siberia, which have implications for stratigraphic correlation of the formations in which they are found.