The Lower Devonian scorpionWaeringoscorpio and the respiratory nature of its filamentous structures, with the description of a new species from the Westerwald area, Germany

The fossil scorpionWaeringoscorpio hefteri Størmer, 1970 (Arachnida: Scorpiones) from the Lower Devonian of the Rhenish Massif of Germany is redescribed based on both the original type and newly collected material. A second, more tuberculate species from Siegenian strata near Bürdenbach in the Westerwald (also part of the Rhenish Massif) is described asW. westerwaldensis n. sp. Details of the coxo-sternal region — including the lack of an oral tube — and the number of ventral mesosomal plates are discussed.Waeringoscorpio Størmer, 1970 is best known for its possession of externally-projecting ‘gills’. Our new material reveals that these are indeed pair-wise bundles of rigid, branching filaments which originate laterally, quite possibly from those segments of the mesosoma associated with the book lungs in extant scorpions. Their gross morphology is most consistent with a respiratory organ adapted for use in water. Indeed their closest modern analogues are the tracheal gills of secondarily aquatic insects. We suggest that the morphology and likely palaeoenvironment ofWaeringoscorpio could indicate an aquatic animal, but we draw attention to the uniqueness of its gill-structures, which may not be part of the scorpion ground-pattern. Thus,Waeringoscorpio was perhaps a secondarily aquatic scorpion adapted for benthic life in oxygen-stressed, freshwater-brackish environments.     

Redescription and palaeobiology of Palaeoscorpius devonicus Lehmann, 1944 from the Lower Devonian Hunsrück Slate of Germany

Abstract: Palaeoscorpius devonicus Lehmann, 1944 is known from only a single specimen, found in the Eschenbach Pit near Bundenbach in the Lower Devonian Hunsrück Slate of Germany. It is a key fossil, having been interpreted both as the most basal member of the Scorpiones and as one of the order’s most likely candidates for an aquatic mode of life. Prepared both ventrally and dorsally, some aspects of its morphology remain problematic. Here, with the aid of new techniques, including computed tomography, we present a re‐investigation of this scorpion’s anatomy and a new reconstruction, with a particular focus on the species’ original habitat. On the basis of the environmental interpretation of the Hunsrück Slate and the completeness of the specimen, previous authors concluded that P. devonicus was marine, but none offered convincing morphological evidence. Recent studies of the deposit’s environment suggest that the Hunsrück Sea was part of an intrashelf basin, relatively close to the coastline, and fossils of land plants show that terrestrial wash‐in occasionally occurred. Our revised interpretation of the fossil’s morphology demonstrates that the scorpion was most probably terrestrial. Internal mesosomal organs are interpreted as book lungs, but other terrestrial adaptations are lacking. The absence of both coxapophyses and gnathobases makes determining the scorpion’s feeding mechanism difficult. Interpreting the scorpion’s character states within a phylogenetic framework, especially the possible presence of book lungs, implies either that the plesiomorphic position of P. devonicus is no longer supported or that the development of book lungs had already taken place early in the scorpion lineage.     

New data on Lepidion schmidti (Gadiformes: Moridae) from the north-east Atlantic Ocean

A new record of Lepidion schmidti (Gadiformes: Moridae) is reported from the Bay of Biscay (north-east Atlantic Ocean). Lepidion schmidti is a rare and poorly known species, scarcely described in the ichthyological literature. Morphometric and meristic characteristics of the specimen are given. A compilation of the specimens caught in the north-east Atlantic Ocean was carried out and the current status of the species in Atlantic waters is discussed. Lepidion schmidti is characterized mainly by the presence of an inverted V-shaped patch of vomerine teeth and a V-shaped crest on the dorsal surface of the head with the apex anterior. The presence of supernumerary anal fin rays in this species is described for the first time. The results obtained confirm the presence of L. schmidti from the north-east Atlantic Ocean.     

Abdominal plates,spiracles and sternites in the ventral mesosoma of embryos of the desert scorpion Paruroctonus mesaensis (Scorpiones,Vaejovidae)

Summary

The scanning electron microscope was used to study changes in the ventral mesosoma of the vaejovid scorpion, Paruroctonus mesaensis. Observations are compared with those from scorpion fossils. The oldest fossils are from the Silurian period; migration from water to land occurred in the Carboniferous and Permian periods. All recent scorpions are terrestrial with four pairs of booklungs and spiracles in mesosomal sternites. Ancient eurypterids and scorpions had flap-like abdominal plates attached to the ventral surface of five mesosomal segments. The abdominal plates were apparently an aquatic adaptation, and authors have described possible gill tissue in the chamber above. In scorpion embryos, rectangular (holostem) plate-like structures precede the formation of sternites in the ventral mesosoma. Transverse folds were seen in the space above the abdominal plates. The lack of elaborate gill-like structures here supports an earlier hypothesis that aquatic scorpions had other mesosomal respiratory sites (e.g., pectines), resulting in less reliance on respiratory tissues above the abdominal plates. Spiracles initially appear as round or ovoid patterns in the epidermis at the latero-posterior margins of the ventral plates. The booklung spiracles are positioned farther anterior in sternites, but the developmental sequence for this transition is still unclear and may occur later than the stages of this study. The abdominal plates lengthen and enlarge laterally and/or epidermis is added at the lateral edges so that broad, overlapping sternites eventually cover the ventral surface of the mesosoma.     

瓦屋山国家森林公园锄足蟾科6种的繁殖鸣声特性

在地处四川省洪雅县的瓦屋山国家森林公园录取了锄足蟾科 6种的繁殖期求偶鸣叫声。它们分隶 4属 ,即角蟾属 (Megophrys)、齿蟾属 (Oreolalax)、齿突蟾属 (Scutiger)和掌突蟾属 (Leptolalax)。在IBMPC上用“SIGNAL”软件 (EngineeringDesign ,USA)对获取的鸣声资料进行分析 ,分析的频率范围设置为 0～ 10kHz。声学分析结果表明 :峨山掌突蟾 (L oshanensi) ,小角蟾 (M minorr) ,角蟾 1种 (M sp) ,金顶齿突蟾[S (S )chintingensis],峨眉齿蟾 (O omeimontis)和无蹼齿蟾 (O schmidti)的主能峰频率平均值分别是45 2 1 9、 34 5 6 4、 2 2 93 8、 10 76 5、 10 71 0和 1849 4Hz ,每声持续时间的平均值分别是 46 2、 90 8、 99 6、72 2、 78 8和 110 3ms ,声距的平均值分别是 140 4、 2 5 3 0、 6 81 4、 15 17 7、 46 1 3和 6 19 5ms。单因子方差分析结果表明主能峰频率、每声持续时间和各声距在 6个种间差异极显著 (P <0 0 1)。LSD法多重比较的结果指出金顶齿突蟾和峨眉齿蟾间的主能峰频率无显著差异 (P =0 917>0 0 5 ) ;在每声持续时间上 ,只有峨山掌突蟾与小角蟾、角蟾 1种、峨眉齿蟾、无蹼齿蟾间差异极显著 (P <0 0 1) ;在声距上 ,峨山掌突蟾与小角蟾间无显著差异 ,角蟾 1种与无蹼齿蟾之间、峨     

A theory on the ancestry of angiosperms

Summary By inferences from fossil records and circumstantial evidences, it is now generally postulated that angiosperms have a much longer history than hitherto believed and that they have already existed probably in Jurassic time. Studies in vascular tissues and reproductive, structures have negated the possibility of originating angiosperms from various gymnosperm groups. Chronologically, this derivation will be also an impossibility.From a consideration of various aspects in the life history of angiosperms, a hypothesis is here presented postulating that protangiosperms originated in an aquatic or subaquatic environment from an algal ancestry. The enclosure of ovules in the ovary is interpretated as a means of protection necessitated for the transmigration from an aquatic to an aerial habitat for the developing reproductive parts in the bud underwater. Trimery is suggested as a primitive condition, one that affords maximum efficiency in carrying out the purpose under the conditions.In the life history of angiosperms, the endosperm is of great significance in phylogeny. From morphological, physiological, cytological as well as genetical considerations, the endosperm should be regarded as of equal status with the gametophytic and sporophytic generations. There is no comparable structure in the gymnosperm groups and the ferns and fern-allies, while more or less similar conditions are present in the thallophytes. In the long life histories of many red algae, however, there is an especially notable resemblance to angiosperms, with certain details approaching the unique and characteristic features of the endosperms.Land plants are presumably all evolved from aquatic ancestors but instead of the usual concept of a monophyletic origin and lineal development of all vascular plants, a more plausible suggestion is the multiple and recurrent derivation of such plants from various algal ancestral groups. The angiosperms probably represent one of such major lines that originated more or less directly from a thallophytic ancestry.     

云南早侏罗世一新具嵴冠兽脚类恐龙

报道了具嵴冠的兽脚类恐龙一新属种,安龙堡双柏龙(Shuangbaisaurus anlongbaoensis gen.et sp.nov.).双柏龙发现于云南省楚雄彝族自治州双柏县下侏罗统冯家河组中,保存了部分头骨带下颌.双柏龙沿两侧眼眶背缘向上有嵴冠发育,这在其他兽脚类中未曾报道过.与其他早侏罗世体型较大且具一对矢状嵴冠的兽脚类(双嵴龙属和中国龙属)相比,双柏龙还独具一些特征组合,如相对较高的前颌骨体、抬高的前颌骨腹缘、后腹向延伸的轭骨后突及较小的上颞孔.比较研究表明,尽管中国“双嵴龙”(“Dilophosaurus”sinensis)可能应归入中国龙属(Sinosaurus),但未必属于模式种.双柏龙的发现将有助于研究基干兽脚类的演化,尤其是各类头骨骨饰在其中的作用.     

The first scorpion fossil from the Cretaceous amber of Myanmar (Burma). New implications for the phylogeny of Buthoidea

A specimen belonging to a new genus and species of fossil scorpion, Palaeoburmesebuthus grimaldii gen. n., sp. n., is described from the Upper Cretaceous amber of Myanmar (Burma). This is the first scorpion to have been found and described from Burmese amber (± 90 Myr). The new genus and species are unquestionable buthoid elements but they are assigned to an incertae familiae until further material may be available for study. To cite this article: W.R. Lourenço, C. R. Palevol 1 (2002) 97–101.     

Diversity of Middle Jurassic Turtles from the Berezovsk Quarry Locality,Krasnoyarsk Region,Russia: Morphology and Histological Study

Abstract—Morphology and histology of several fragmentary turtle specimens from the Middle Jurassic locality in the Berezovsk quarry (Krasnoyarsk Region, Russia) are described, including Testudines indet. 1 (costal VIII), Testudines indet. 2 (two ornamented shell fragments), and Testudines indet. 3 (distal part of a humerus), and also skeletal elements of Annemys sp. (Xinjiangchelyidae) represented by mass material in the same locality. It is shown that Testudines indet. 1 and 3 probably belong to one or two taxa of basal aquatic turtles, while Testudines indet. 2 is most likely an abnormal Annemys sp. The presumable presence of basal turtles in the Berezovsk Quarry Assemblage agrees with the fact that they are present in other Middle Jurassic turtle assemblages of Asia.     

Reworked carboniferous spores: An example from the lower jurassic of northeast Scotland

An association of contemporaneous Jurassic mega- and miospores with reworked Carboniferous mega- and miospores is described from the Lower Lias rocks of northeast Scotland. The assemblage is compared with other accounts of reworked spores in Jurassic sediments. It is suggested that such reworking was particularly common in the Lower Jurassic of northern Europe and that four situations exist in the literature concerning probable cases of reworking: (1) the spores are recognised as reworked; (2) the identity of the spores as Carboniferous species is recognised and the “range” of these species is extended into the Jurassic; (3) the reworked spores are not recognised as such, and are incorrectly assigned to Jurassic genera and species; (4) the spores are recognised as Carboniferous, but their origin is attributed to contamination rather than reworking. In conclusion, the contrasting preservational features exhibited by the reworking and contemporaneous megaspores are discussed and interpreted as the result of differing depositional and postdepositional histories.     

Immunological correspondence between arthropod hemocyanin subunits. I. Scorpion (Leiurus, Androctonus) and spider (Eurypelma, Cupiennius) hemocyanin

The hemocyanins of the scorpions Leiurus quinquestriatus and Androctonus australis, the tarantula Eurypelma californicum (all 24-mers), and the lycosid spider Cupiennius salei (dodecamer) were dissociated into subunits, the subunits isolated and studied by two-dimensional immunoelectrophoresis for interspecific cross-reactivities. Androctonus hemocyanin yielded a pattern of 8 subunit types in agreement with data from Lamy et al. (1979, Arch. Biochem. Biophys. 193, 140-149). Leiurus hemocyanin is also composed of 8 immunologically distinct subunits which could be assigned to the pattern of Androctonus in a subunit-to-subunit correlation. The subunit designations 1 to 6 of Lamy et al. could be adopted for both scorpion hemocyanins; however, in the present communication, Lamy's subunits 3A/3B are designated as 3'/3", because we could not unequivocally decide if 3' = 3A and 3" = 3B or vice versa. The 7 subunit types a to g of Eurypelma hemocyanin could be correlated with the scorpion hemocyanin subunits as follows: a = 3', b = 5B, c = 3C, d = 5A, e = 6, f = 2, g = 4. Additional cross-reactivities were detected between e/4, and f/5A, respectively. No subunit of Eurypelma hemocyanin is homologous to scorpion 3", which could not be precipitated by anti-Eurypelma antiserum. Antiserum against Cupiennius hemocyanin precipitated subunit f of Eurypelma and subunits 2 and 5A of scorpion hemocyanin. The published models of quaternary structure and a possible subunit phylogeny of arachnidan hemocyanins are discussed in view of the present results.     

重庆晚侏罗世两处兽脚类足迹组合与四川盆地侏罗纪地层(英文)

重庆市已报道了4处侏罗纪的恐龙足迹点,包括下侏罗统珍珠冲组的大足化石点,该地点发现了中国迄今最古老的蜥脚类行迹;另外两处化石点(南岸和金鸡)的层位曾被视为中或上侏罗统,这里首次将其确认为上侏罗统上沙溪庙组;第4处化石点(成渝), 本文全部作者目前都未曾观察,这里不做描述。南岸化石点是南岸重庆足迹(Chongqingpus nananensis)模式标本的所在地,位于重庆市中心,曾发现过大量兽脚类足迹,如今已消逝在城市化进程中。幸运的是,这批标本被保存于重庆自然博物馆,本文作者曾前后两次对其进行研究,并得出文中的结论。南岸重庆足迹为中型足迹(平均长约29 cm), 最可能被卡岩塔足迹(Kayentapus)所囊括,这批标本中有一些保存着边界不清的拇趾迹。该化石点的其他足迹被归于似异样龙足迹(cf. Anomoepus)。其他较小的、来自重庆市周边中侏罗统中部的足迹此前已被归于跷脚龙足迹(Grallator)。金鸡化石点保存了一条孤立的兽脚类行迹,因其粗壮的特征而被暂时归于似窄足龙足迹(cf. Therangospodus)。金鸡点的行迹也保存了非连续出现的拇趾迹。虽然重庆市和四川盆地及其周边更广泛地区之侏罗纪地层发现的兽脚类足迹日渐增多,但要明确其确切地质年龄及有效的足迹分类依然需要进一步工作。这是因为侏罗纪的恐龙足迹尽管丰富,但显示出连续变化的形态学特征,而保存状况的变化更使其难以在时间与空间上做出定义与鉴别。     

Low-molecular-weight compounds with anticoagulant activity from the scorpion <Emphasis Type="Italic">Heterometrus laoticus</Emphasis> venom

Low-molecular-weight compounds with anticoagulant activity were isolated from the scorpion Heterometrus laoticus venom. The determination of the structure of the isolated compounds by nuclear magnetic resonance and mass spectrometry showed that one of the isolated compounds is adenosine, and the other two are dipeptides leucyl-tryptophan and isoleucyl-tryptophan. The anticoagulant properties of adenosine, which is an inhibitor of platelet aggregation, is well known, but its presence in scorpion venom is shown for the first time. The ability of leucyl-tryptophan and isoleucyl-tryptophan to slow down blood clotting and their presence in scorpion venom are also established for the first time.     

Bone histology of the Middle Jurassic turtle shell remains from Kirtlington, Oxfordshire, England

The Middle Jurassic (Bathonian) turtle material from the Mammal Bed at Kirtlington, Oxfordshire, England, has recently been tentatively referred to the Pleurosternidae, although the known synapomorphies of this clade were absent from the specimens. Here we present new evidence from shell bone histology that corroborates reports of pleurosternids at Kirtlington and further reveal that two different histomorphs (= two different taxa) are present in this locality. The first histomorph presents the distinctive histological structure of pleurosternids, which is described herein for the first time: the external cortical bone layers are differentiated into an inner zone of coarse, irregularly interwoven structural fibre bundles and an outer fine-fibred zone. The second histomorph has a more plesiomorphic structure and can only be assigned to Cryptodira indet. A morphological reassessment of the Kirtlington material fails to recognize two different taxa and shows that only sparse evidence supports the presence of pleurosternids in this locality. Shell bone histology thus appears as a powerful tool to study poorly preserved specimens and may in some case (like with pleurosternids) help resolve phylogenetic relationships. According to our results, the stratigraphic appearance of the Pleurosternidae is adjusted from the Kimmeridgian (Late Jurassic) to the Bathonian (Middle Jurassic), which significantly reduces the ghost lineage of Paracryptodira.     Bone histology, turtles, Paracryptodira, Pleurosternidae, Middle Jurassic, Kirtlington.     

Motions and structural variability within toxins: implication for their use as scaffolds for protein engineering

Animal toxins are small proteins built on the basis of a few disulfide bonded frameworks. Because of their high variability in sequence and biologic function, these proteins are now used as templates for protein engineering. Here we report the extensive characterization of the structure and dynamics of two toxin folds, the "three-finger" fold and the short alpha/beta scorpion fold found in snake and scorpion venoms, respectively. These two folds have a very different architecture; the short alpha/beta scorpion fold is highly compact, whereas the "three-finger" fold is a beta structure presenting large flexible loops. First, the crystal structure of the snake toxin alpha was solved at 1.8-A resolution. Then, long molecular dynamics simulations (10 ns) in water boxes of the snake toxin alpha and the scorpion charybdotoxin were performed, starting either from the crystal or the solution structure. For both proteins, the crystal structure is stabilized by more hydrogen bonds than the solution structure, and the trajectory starting from the X-ray structure is more stable than the trajectory started from the NMR structure. The trajectories started from the X-ray structure are in agreement with the experimental NMR and X-ray data about the protein dynamics. Both proteins exhibit fast motions with an amplitude correlated to their secondary structure. In contrast, slower motions are essentially only observed in toxin alpha. The regions submitted to rare motions during the simulations are those that exhibit millisecond time-scale motions. Lastly, the structural variations within each fold family are described. The localization and the amplitude of these variations suggest that the regions presenting large-scale motions should be those tolerant to large insertions or deletions.     

Antarease-like Zn-metalloproteases are ubiquitous in the venom of different scorpion genera

Background

The venoms of several scorpion species have long been associated with pancreatitis in animal models and humans. Antarease, a Zn-metalloprotease from Tityus serrulatus, is able to penetrate intact pancreatic tissue and disrupts the normal vesicular traffic necessary for secretion, so it could play a relevant role in the onset of acute pancreatitis.

Methods

The cDNA libraries from five different scorpion species were screened for antarease homologs with specific primers. The amplified PCR products were cloned and sequenced. A structural model was constructed to assess the functionality of the putative metalloproteases. A phylogenetic analysis was performed to identify clustering patterns of these venom components.

Results

Antarease-like sequences were amplified from all the screened cDNA libraries. The complete sequence of the antarease from T. serrulatus was obtained. The structural model of the putative antarease from Tityus trivittatus shows that it may adopt a catalytically active conformation, sharing relevant structural elements with previously reported metalloproteases of the ADAM family. The phylogenetic analysis reveals that the reported sequences cluster in groups that correlate with the geographical localization of the respective species.

Conclusions

Antareases are ubiquitous to a broad range of scorpion species, where they could be catalytically active enzymes. These molecules can be used to describe the evolution of scorpion venoms under different ecogeographic constrains.

General significance

For the first time the complete sequence of the antareases is reported. It is demonstrated that antareases are common in the venom of different scorpion species. They are now proposed as targets for antivenom therapies.     

First Thyreophoran Type Tracks from the Middle Jurassic Chuanjie Formation of Yunnan Province,China

Two tridactyl footprints from the Chuanjie Formation (Middle Jurassic) of Yunnan Province, China are morphological characteristics of thyreophoran tracks. They show some similarities to Shenmuichnus, known from the Early Jurassic strata of both Shaanxi and Yunnan provinces, but are somewhat larger, thereby resembling the ichnogenus Stegopodus. Based on their general morphology and size being congruent with this ichnogenus, they are tentatively assigned here to cf. Stegopodus. This is the fourth report of large ornithischian (probably thyreophoran) tracks from the Lower-Middle Jurassic of China that indicates relatively large trackmakers that were likely to be taxonomically distinct from much smaller and gracile Anomoepus trackmakers, also of ornithischian affinity. The larger tracks indicate a hitherto unreported abundance, size range and diversity of track types attributed to this group. The parallel orientation of the two best preserved trackways may indicate gregariousness.