scholarly journals Comparing amber fossil assemblages across the Cenozoic

2006 ◽  
Vol 2 (2) ◽  
pp. 266-270 ◽  
Author(s):  
David Penney ◽  
A. Mark Langan

To justify faunistic comparisons of ambers that differ botanically, geographically and by age, we need to determine that resins sampled uniformly. Our pluralistic approach, analysing size distributions of 671 fossilized spider species from different behavioural guilds, demonstrates that ecological information about the communities of two well-studied ambers is retained. Several lines of evidence show that greater structural complexity of Baltic compared to Dominican amber trees explains the presence of larger web-spinners. No size differences occur in active hunters. Consequently, we demonstrate for the first time that resins were trapping organisms uniformly and that comparisons of amber palaeoecosystem structure across deep time are possible.

Zootaxa ◽  
2021 ◽  
Vol 4927 (2) ◽  
pp. 197-208
Author(s):  
FRANCESCO BALLARIN ◽  
TAKESHI YAMASAKI ◽  
YONG-CHAO SU

Representatives of some poorly known spider species collected in the rainforest litter of the Orchid Island (Taiwan) are illustrated and discussed here. A new species, Brignoliella tao sp. nov. (Fam. Tetrablemmidae), endemic to Orchid Island, is described based on both sexes. The previously unknown female of Theridiosoma triumphale Zhao & Li, 2012 (Fam. Theridiosomatidae), is described for the first time. Zoma taiwanica (Zhang, Zhu & Tso 2006) comb. nov., from the same family, is illustrated and its transfer from the genus Theridiosoma O. Pickard-Cambridge, 1879 to Zoma Saaristo, 1996 is proposed on the basis of morphological characters. Habitus and genitalia of the endemic species Gongylidioides angustus Tu & Li, 2006 (Fam. Linyphiidae) are also illustrated. 


2014 ◽  
Vol 936 ◽  
pp. 942-949 ◽  
Author(s):  
Hao Tian Zhang ◽  
Qiu Yu Zhang ◽  
Bao Liang Zhang ◽  
Chun Mei Li

Porous properties have notable effect on separating effect of organic polymer-based monolithic column. Different applications of monolithic columns require tailored pore size distributions. On account of that, P(GMA-co-EGDMA) monolithic columns were prepared with novel ternary porogenic agents. Glass tubes was chosen as polymerization mold. Moreover, factors influencing the inner pore morphology, pore size and specific surface area were investigated systematically. The results showed that the increasing of the solubility of porogenic agents and the amount of crosslinker, the decreasing of the amount of porogenic agents and temperature rising all could give rise to the decreasing of pore size. Remarkably, the effect of initiator was studied for the first time. The results showed that amount of initiator had no remarkable influence on porous properties. By controlling effect factors, P(GMA-co-EGDMA) Monolithic Columns with pore size from dozens to thousands of nanometer, which can be applied in separation of molecules with different size.


Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 285
Author(s):  
Enrico Lunghi ◽  
Fabio Cianferoni ◽  
Stefano Merilli ◽  
Yahui Zhao ◽  
Raoul Manenti ◽  
...  

Speleomantes are the only plethodontid salamanders present in Europe. Multiple studies have been performed to investigate the trophic niche of the eight Speleomantes species, but none of these studies included hybrid populations. For the first time, we studied the trophic niche of five Speleomantes hybrid populations. Each population was surveyed twice in 2020, and stomach flushing was performed on each captured salamander; stomach flushing is a harmless technique that allows stomach contents to be inspected. We also assessed the potential divergence in size and body condition between natural and introduced hybrids, and their parental species. Previously collected data on Speleomantes were included to increase the robustness of these analyses. In only 33 out of 134 sampled hybrid Speleomantes we recognized 81 items belonging to 11 prey categories. The frequency of empty stomachs was higher in females and individuals from natural hybrid populations, whereas the largest number of prey was consumed by males. We compared the total length and body condition of 685 adult salamanders belonging to three types of hybrids and three parental (sub)species. Three group of salamanders (one hybrid and two parental species) showed significantly larger size, whereas no difference in body condition was observed. This study provided novel ecological information on Speleomantes hybrid populations. We also provided insights into the potential divergence between hybrids and parental species in terms of size and body condition. We discuss our findings, and formulate several hypotheses that should be tested in the future.


2014 ◽  
Vol 74 (2) ◽  
pp. 483-488
Author(s):  
R. Campitelli-Ramos ◽  
JV. Lucca ◽  
LLD. Oliveira ◽  
MR. Marchese ◽  
O. Rocha

Annelid worms represent a significant part of freshwater benthic communities worldwide and Oligochaeta is a particularly species-rich group. Dero (A) bimagnasetus (Naididae) previously found and described from a small marsh in Surinam in 1974, has now been found for the first time in Barra Lake, MG, Brazil. Due to the scarce biological data and absence of ecological information in the literature regarding this species we are presenting morphological information on the specimens obtained and the physical and chemical characteristics of the habitat they were found. This species occurred only in the littoral zone of Barra Lake, in muddy, low oxygen, low conductivity and low organic matter sediment. The four individuals collected ranged 3.17-4.15 mm total length; 0.25 - 0.26 mm body width and 0.16-0.21 mm3 total volume. Considering the present anthropic pressures on freshwater biota and fast biodiversity losses worldwide it is now recognized that attention must be paid to low abundance species and the urgency for preservation of their habitats.


PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e1301 ◽  
Author(s):  
Adiël A. Klompmaker ◽  
Roger W. Portell ◽  
Aaron T. Klier ◽  
Vanessa Prueter ◽  
Alyssa L. Tucker

Spider crabs (Majoidea) are well-known from modern oceans and are also common in the western part of the Atlantic Ocean. When spider crabs appeared in the Western Atlantic in deep time, and when they became diverse, hinges on their fossil record. By reviewing their fossil record, we show that (1) spider crabs first appeared in the Western Atlantic in the Late Cretaceous, (2) they became common since the Miocene, and (3) most species and genera are found in the Caribbean region from the Miocene onwards. Furthermore, taxonomic work on some modern and fossil Mithracidae, a family that might have originated in the Western Atlantic, was conducted. Specifically,Maguimithraxgen. nov. is erected to accommodate the extant speciesDamithrax spinosissimus, whileDamithraxcf.pleuracanthusis recognized for the first time from the fossil record (late Pliocene–early Pleistocene, Florida, USA). Furthermore, two new species are described from the lower Miocene coral-associated limestones of Jamaica (Mithrax arawakumsp. nov. andNemausa windsoraesp. nov.). Spurred by a recent revision of the subfamily, two known species from the same deposits are refigured and transferred to new genera:Mithrax donovanitoNemausa, andMithrax unguistoDamithrax. The diverse assemblage of decapods from these coral-associated limestones underlines the importance of reefs for the abundance and diversity of decapods in deep time. Finally, we quantitatively show that these crabs possess allometric growth in that length/width ratios drop as specimens grow, a factor that is not always taken into account while describing and comparing among taxa.


Zootaxa ◽  
2021 ◽  
Vol 5082 (3) ◽  
pp. 278-285
Author(s):  
WEN-JING DING ◽  
JIAN-HUA DING ◽  
HAI-JUN ZHANG ◽  
LING-SHENG ZHA

Tetrix gibberosa (Wang & Zheng) is a high-backed pygmy grasshopper species from eastern PR China. Due to its reduced hind wings and pleomorphism (length changes of hind wings and the hind pronotal process, which is generally called macropterous and brachypterous morphs), the species have been described into different species which involve several taxonomically confused genera. This study clarifies its taxonomy and distribution and provides ecological information for the species. At the same time, we comment the relationships of related genera in the subfamily Tetriginae, including Tetrix Latreille, Exothotettix Zheng & Jiang, Alulatettix Liang, Aalatettix Zheng & Mao, Formosatettix Tinkham, and Formosatettixoides Zheng. Additionally, we report for the first time that nematodes can parasitize pygmy grasshoppers. New synonyms are proposed: Tetrix gibberosa (Wang & Zheng, 1993) = Alulatettix bulbosus Zheng & Zhong, 2001, syn. nov., = Exothotettix jiangxiensis Liang & Jia, 2008, syn. nov., = Tetrix glochinota Zhao, Niu & Zheng, 2010, syn. nov., = Alulatettix nigromarginalis Zhang, Deng & Zha, 2014, syn. nov., = Alulatettix flavotibialis Zhang, Deng & Zha, 2014, syn. nov..  


2020 ◽  
Vol 196 (4) ◽  
pp. 454-471 ◽  
Author(s):  
Simon A. F. Darroch ◽  
Michelle M. Casey ◽  
Gwen S. Antell ◽  
Amy Sweeney ◽  
Erin E. Saupe

Zootaxa ◽  
2019 ◽  
Vol 4612 (3) ◽  
pp. 423
Author(s):  
QIQI ZHANG ◽  
YUCHENG LIN

Two new species the spider family Anapidae are described from Southeast Asia: Conculus sagadaensis n. sp. from Philippines and Conculus yaoi n. sp. from Indonesia, both described after male specimens. Conculus is reported from Southeast Asia for the first time. Diagnoses and illustrations are provided for two new species. The types are deposited in the Natural History Museum of Sichuan University (NHMSU) in Chengdu, China. 


Geology ◽  
2020 ◽  
Vol 48 (4) ◽  
pp. 338-342
Author(s):  
Manuel F. Isla ◽  
Ernesto Schwarz ◽  
Gonzalo D. Veiga

Abstract The morphology of wave-dominated clastic shorelines (i.e., foreshore and upper-shoreface sediments) can vary from barred to nonbarred, though the ancient record of nonbarred, sand-dominated shorelines has yet to be recognized. Here, a facies and quantitative architectural analysis of a clastic succession characterized by sandy inclined beds is presented and interpreted as the record of a high-gradient, nonbarred shoreline. Inclined beds dip seaward, have a tangential geometry (<3 m height, <40 m length, <11° dip), and are composed of planar lamination along the foresets and subordinate small-scale trough cross-bedding in the bottomsets. This facies distribution reflects a steep beach profile with a narrow surf zone and the development of plane beds both in foreshore and proximal upper-shoreface settings. Successive packages of inclined beds (a few tens of meters wide) are interpreted as the seaward accretion of this shoreline morphology, producing distinctive architectural elements (foresets and bottomsets). For the first time, we propose diagnostic criteria for identification in the rock record of the widely used modern nonbarred clastic shoreline model, and we contrast them with classical facies models of barred systems. Moreover, we discuss similarities and differences with radar-based Holocene coastal architectural elements, highlighting the need to incorporate detailed two-dimensional quantitative studies for refining the reconstruction of deep-time and recent clastic shorelines.


2011 ◽  
Vol 182 (3) ◽  
pp. 231-240 ◽  
Author(s):  
Jérémy Anquetin

AbstractIn recent years, no less than five new species of early turtles have been described worldwide. Among them are three new turtles from Middle Jurassic deposits that partially fill a previous temporal and morphological gap in our knowledge of the early evolution of these shelled amniotes: Heckerochelys romani, Condorchelys antiqua and Eileanchelys waldmani. For the first time, the phylogenetic position of these three new species is tested in the context of the two presently competing cladistic models of turtle evolution. The addition of these taxa to each matrix does not favour or alter any of the two opposed hypotheses. However, it is demonstrated here that, by documenting yet unknown stages in the evolution of several morphological structures, these three species give stronger support to the model of an extended phylogenetic stem for turtles. These new lines of evidence include the structure of the vomer, the position of the aditus canalis stapedio-temporalis and of the posterior opening of the canalis cavernosus, and the morphology of the processus interfenestralis of the opisthotic.Recent discoveries also reinvigorate the debate about the palaeoecology of early turtles. Whereas simple morphological characters (e.g., shell fontanelle, ligamentous bridge, flattened carapace) can be misleading, forelimb proportions and shell bone histology have led to the conclusion that most stem turtles (i.e., Proganochelys quenstedti, Palaeochersis talampayensis, Proterochersis robusta, Kayentachelys aprix and meiolaniids) were terrestrial forms. At least two out of the five recently described early turtles have been convincingly interpreted as having aquatic habits: Odontochelys semitestacea and Eileanchelys waldmani. More investigation is needed, but this will undoubtedly trigger further debate on the primitive ecology of turtles and on the origin of aquatic habits in testudines (i.e., the crown-group), respectively.


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