Unique Combination Of Characters Research Articles

A new plastomenid trionychid (Testudines: Pan-Trionychidae) from Milk River Formation of southern Alberta (Cretaceous: Santonian)

The pre-Campanian trionychid fossil record in North America is composed of highly fragmentary specimens, which are often not identifiable beyond Pan-Trionychidae. Here, we describe a new species of plastomenid soft-shelled turtle based on a partial shell (ROM 56647) from the Santonian Milk River Formation of southern Alberta, estimated at approximately 84 Ma. This represents the oldest relatively complete shell of a trionychid from North America. Plastomenidae, a pan-trionychid clade known only from the fossil record, is classically characterized by the complete suturing of its posterior plastral bones along the midline, a crescent-shaped entoplastron, and enlarged costals VIII. ROM 56647 has a unique combination of plastomenid characters (i.e., mid-line contact of hypoplastra and xiphiplastra, anteroposteriorly long eighth costal) and apomorphies (an emarginate nuchal, enlarged tubercles on the carapace, a wide pygal notch with a straight anterior edge, and a fused hyo-hypoplastron) that allows us to identify it as a new taxon, Jimemys glaebosus gen. et sp. nov. Phylogenetic analysis places J. glaebosus within Plastomenidae as the sister taxon to a clade containing Plastomenus, Helopanoplia, and Hutchemys. This phylogenetic position implies that Aspideretoides foveatus Leidy, 1856, Atoposemys, and Gilmoremys, all of which are more basal within Plastomenidae, had ghost lineages extending at least to the Santonian. As the oldest pan-trionychid that is diagnostic to the species level in North America, J. glaebosus provides new insights into both the early evolution of trionychids in North America and the biodiversity of southern Alberta during a poorly sampled time in the Late Cretaceous of North America.

Orostylis gen. nov., a new genus of Dalytyphloplanida with seven new species (Platyhelminthes: Rhabdocoela)

We describe a new genus of dalytyphloplanid rhabdocoels, with seven new species. Orostylis gen. nov. has a unique combination of characters including the presence of a sclerotised stylet, an anteriorly positioned male copulatory organ with the male genital pore in the buccal cavity, and the absence of an oviduct. The ovary empties directly into the intestinal lumen. Orostylis dohae sp. nov., Orostylis asinaraensis sp. nov., Orostylis caecus sp. nov., Orostylis distortus sp. nov., Orostylis donanae sp. nov., Orostylis gallicus sp. nov., and Orostylis timucuorum sp. nov. are distinguished from each other by the structure of the sclerotised parts of the male copulatory organ. Molecular and morphological evidence place the new genus in Neodalyellida Willems et al. 2006, and similarities with other taxa are discussed.

A new genus and new species of potamid crab from Yunnan, southern China (Decapoda: Brachyura: Potamidae: Potamiscinae)

Abstract A new genus and new species of freshwater crab, Barbamon zhouigen. nov., sp. nov., belonging to the subfamily Potamiscinae Bott, 1970 (Potamidae Ortmann, 1896) is described from Wenshan Zhuangzu and Miaozu Autonomous Prefecture, Yunnan Province, China. The new genus is established based on a unique combination of characters, including the distinctive shape of the male first gonopod, and the setose ventral surface of the third maxilliped, suborbital and pterygostomial regions, and ambulatory legs. Barbamongen. nov. is similar in external appearance to AbormonMitra, Pati & Ng, 2021. The new genus, however, is distinctive in the combination of characters related to the carapace, third maxilliped, and male first gonopod. Molecular phylogenetic data derived from mitochondrial 16S rDNA sequences provides genetic support for the new genus and species.

A New Species of Xenosaurus (Squamata: Xenosauridae) from the Sierra de Juárez of Oaxaca, Mexico

We describe a new species of Knob-scaled Lizards of the genus Xenosaurus from the Sierra de Juárez of Oaxaca, México. Although this new species was identified as a distinct, undescribed lineage (and sister taxon to X. grandis) by previous molecular phylogenetic studies of the genus, we documented that it also differs from all of its congeners by a unique combination of scalation and color-pattern characters. The new species also is geographically isolated from all congeners and appears to have a geographic distribution limited to the vicinity of its type locality, between 1400 m and 1800 m of elevation, in the cloud forest belt of the Sierra de Juárez. Because the new species is a terrestrial, crevice-dwelling species generally ignored by humans and has a limited geographic and ecological distribution, we calculated its Environmental Vulnerability Score at 17, which places it in the middle of the high category of vulnerability to environmental degradation.

Reappraisal and new material of the holotype of Draconyx loureiroi (Ornithischia: Iguanodontia) provide insights on the tempo and modo of evolution of thumb-spiked dinosaurs

Abstract The Upper Jurassic Lourinhã Formation is well known for its rich assemblage of fossil vertebrates. In this formation, ornithopod dinosaurs are represented by two iguanodontian species, Eousdryosaurus nanohallucis and Draconyx loureiroi. We recently became aware of unreported material belonging to the holotype of Draconyx loureiroi, consisting of partially articulated manual elements. We here re-describe the holotype specimen ML 357, including the newly discovered material. The specimen was subjected to CT-scanning and its surface data used to assess anatomical characters. Linear measurements of metatarsal III were used to estimate the body length of the specimen. The Draconyx loureiroi holotype was included in two datasets and analysed with maximum parsimony and Bayesian inference approaches to estimate evolutionary rates among Iguanodontia. We present evidence that Draconyx loureiroi is a valid taxon nested in Styracosterna and is clearly diagnosable by a unique combination of characters. Both maximum parsimony and Bayesian inference indicate high evolutionary rates across the Jurassic/Cretaceous transition for the base of Iguanodontia. Length estimation suggests that Draconyx loureiroi was a relatively small, bipedal and possibly cursorial animal. Given its basal phyletic position, we interpret this bauplan was the ancestral condition for Styracosterna, that only later in the Cretaceous evolved into giant quadrupedal forms.

A new species of Cyrtodactylus Gray, 1827 (Squamata, Gekkonidae) from southwestern Yunnan, China.

A new species of the Cyrtodactyluschauquangensis species group is described based on four specimens collected from the karst formations of Menglian County, Puer City, Yunnan Province, China. The new species can be separated from all other congeners by having a unique combination of morphological characters: a medium-sized body; ventrolateral folds present with interspersed small tubercles; seven precloacal pores in a continuous series in males, absent in females; enlarged femoral scales and femoral pores absent; two postcloacal tubercles on each side; and one or two rows of enlarged subcaudals. Genetically, the new species most closely related to C.wayakonei and the uncorrected sequence divergences of the ND2 gene and its flanking tRNAs between the new species and investigated congeners range from 7.2% to 18.4%.

Two new species of the previously monospecific genus Guipuzcosoma Vicente amp; Mauris, 1980 from Spain, with establishment of Guipuzcosomatidae fam. nov. (Diplopoda: Chordeumatida).

The present paper refers to the description of two new species of the previously monospecific genus Guipuzcosoma, viz., Guipuzcosoma karinae sp. nov. and G. reipi sp. nov. Given the unique combination of characters of this genus, we have established a higher taxonomic category, Guipuzcosomatidae fam. nov., which is clearly different from the family Vandeleumatidae, to which Guipuzcosoma was assigned earlier. Based on the structures of the anterior and posterior gonopods, we speculate that the new family may belong to the superfamilies Anthroleucosomatoidea or Cleidogonoidea. A diagnosis of the family, a brief description of the genus, as well as a diagnosis of all three species and detailed descriptions with illustrations of the two new species are presented. All three species were mapped. Additionally, some problems related to the taxonomy and classification within Chordeumatida, as well as the hypothetical association of the new family with some other chordeumatidans, are briefly discussed. Finally, the monospecific genus Miniusoma Mauris, 2014 is transferred here from the family Vandeleumatidae to the family Anthogonidae.

Huchimingia, a new genus segregated from Millettia (Leguminosae, Millettieae) based on morphological and molecular evidence

Millettia Wight & Arn. is a heterogeneous genus within the tribe Millettieae (Leguminosae) and has long been used as a repository to accommodate all undistinctive species of the tribe with elastically dehiscent pods. Millettia sect. Podocarpae Dunn is representative of the heterogeneous genus. This section includes five Asian species that have a unique combination of characters that distinguishes them from all other species of the genus, including the deciduous tree habit, conspicuous buds covered with scales, pseudoracemes or pseudopanicles with very indistinct brachyblasts, two flowers per brachyblast, conspicuous large bracts, ebracteolate calyx, well-developed hypanthium, stipitate ovary, and flat, stipitate and dehiscent pods. Our molecular phylogeny based on plastid matK and nuclear ribosomal ITS sequences also suggested the section is clearly monophyletic, separate from other congeneric species, and is most closely related to Antheroporum Gagnep. with inflated, vacuous pods and Ohashia X.Y. Zhu & R.P. Zhang with indehiscent flat pods. Therefore, we propose a new genus, Huchimingia Z.Q. Song & Shi J. Li, to accommodate this distinct section.

First record of the spider family Hersiliidae (Araneae) from the Mesozoic of Europe (Bakony Mts, Hungary)

An adult male Hersiliidae spider is described from amber that originates from the Upper Cretaceous (Santonian) Ajka Coal Formation (Ajka-Csingervölgy, Hungary), the so-called ajkaite. The spider has elongate posterior spinnerets and a short third pair of legs III, both characteristics of the family, but differs from all known Mesozoic (discovered in burmite) and fossil and Recent European representatives of Hersiliidae so that a new genus and species name is proposed for Hungarosilia verdesi gen. et sp. nov. The new taxon is distinguishable by the following unique combination of characters: pro- and opisthosoma nearly circular in dorsal view; posterior spinnerets with a distal article more than three times longer than the basal article; pedipalpal tibia and patella short and stout but pedipalpal femur as long as the cymbium, cymbium egg-shaped and without cymbial apophysis; bulbus of circular shape in ventral view and slightly flattened is lateral view. The fossil represents the first record of Hersiliidae from the Mesozoic of Europe and establishes the second record of this family in the Mesozoic Era. The estimated paleoclimate and paleoflora of the Ajka coal sub-basin correspond well with habitat preferences of Recent relatives that are often arborical and found in association with tree bark. Overall, our findings highlight the importance of a neglected amber type, the ajkaite, for documenting and studying the European arthropod fauna during the Mesozoic.

New combinations and re-lectotypification in the genus Imbralyx (Fabaceae: Millettieae)

Imbralyx R. Geesink (Fabaceae: Millettieae) was long recognized as part of the genus Fordia Hemsl. However, Imbralyx has a unique characteristic combination of characters within Millettieae and it can be readily distinguished from Fordia and other genera of the tribe, including transitional inflorescences to pseudoracemes, distinctly imbricate calyx lobes in buds, spindle-shaped flowerbuds, white flowers, distinct hypanthium, monadelphous stamens, and glabrous leaflets with raised nervation on both surfaces. Recent molecular evidence also suggested that Imbralyx should be treated as a genus distinct from Fordia, because the two genera were placed respectively in two different main subclades within the core Millettieae, i.e. Canavanine group and Non-canavanie group, which is consistent with previous chemical evidence. So far the genus Imbralyx comprises nine species and two varieties from Asia, but only one epithet has been definitely associated with the generic name. Therefore, ten new combinations in Imbralyx are proposed in this paper. Additionally, lectotypes are re-designated here for the two basionyms Millettia albiflora Prain and M. unifoliata Prain.

A remarkable new species of Hypogastrura (Collembola, Hypogastruridae) from the Romanian Carpathiansnbsp.

A new species of Hypogastrura from the Romanian Carpathians is described and illustrated. The new species is characterised by unique combination of morphological characters: presence of seven ocelli, the antennal segment IV with 4 thin, cylindrical sensilla, the presence of 5 setae on ventral tube, the short anal spines situated on high papillae and distinct chaetotaxy. The species is not easy to classify in the present system of the generic subdivision. Considering the presence of only 7+7 ocelli, the new species can be compared only with H. pyrenaica (Cassagnau, 1959), while in other morphological features it is similar to H. aterrima Yosii, 1972 and H. tethyca Ellis, 1976. The similarity between these species and systematic position of the new species are discussed.

An unusual elateroid lineage from mid-Cretaceous Burmese amber (Coleoptera: Elateroidea)

We here report a new elateroid, Anoeuma lawrencei Li, Kundrata and Cai gen. et sp. nov., from mid-Cretaceous Burmese amber. Though superficially similar to some soft-bodied archostematans, Anoeuma could be firmly placed in the polyphagan superfamily Elateroidea based on the hind wing venation. Detailed morphological comparisons between extant elateroids and the Cretaceous fossils suggest that the unique character combination does not fit with confidence into any existing soft-bodied elateroid group, although some characters indicate possible relationships between Anoeuma and Omalisinae. Our discovery of this new lineage further demonstrates the past diversity and morphological disparity of soft-bodied elateroids.

A New Dromaeosaurid (Dinosauria: Coelurosauria) from Khulsan, Central Mongolia

Dromaeosaurid theropods represent a rare but important clade of nonavialan dinosaurs. Their close evolutionary relationship to modern birds has placed them at the center of paleontological research for the last several decades. Herein we describe a new species of dromaeosaurid—Kuru kulla, gen. et sp. nov.—based on a partial skeleton from the Late Cretaceous Khulsan locality (Barun Goyot Formation) of Mongolia. This species is diagnosed by several autapomorphies within Dromaeosauridae, including a sharp groove anterior and ventral to the narial fossa on the premaxilla, a posterolaterally directed hornlet on the posterodorsal process of the lacrimal, a deep surangular bearing two surangular foramina, and anteriorly displaced pleurocoels on the dorsal centra. The taxon is further characterized by a unique combination of characters, including a mediolaterally narrow metatarsal II, serrations on both carinae of the dentary teeth, hyposphenes that are widely separated but joined by a web of bone, and a lacrimal with a poorly developed boss on its lateral surface. Phylogenetic analysis finds Kuru kulla to be the sister taxon of Adasaurus mongoliensis, from the slightly later Nemegt Formation, with which it is united by three synapomorphies: a posterior surangular foramen that is ∼30% the depth of the surangular, absence of a fourth trochanter of the femur, and thoracic centra that are markedly longer than their midpoint widths. The recognition of this taxon has important implications for common assumptions of Mesozoic terrestrial ecosystem structure and adds new data to a recently recognized pattern in dromaeosaurid faunal composition among Late Cretaceous localities in Mongolia and Inner Mongolia (Nei Mongol Autonomous Region, China).

MÔ TẢ LOÀI CÁ CHIÊN BẸT Pareuchiloglanis sp. (SILURIFORMES: SISORIDAE) Ở LƯU VỰC SÔNG ĐÀ, ĐỊA PHẬN HUYỆN PHONG THỔ, TỈNH LAI CHÂU

The genus Pareuchiloglanis (Siluriformes: Sisoridae) consists of 26 species in the world. In Vietnam, this genus has eight species, including five that are in uncertain taxonomy status. In the present study, we described one species of Pareuchiloglanis based on collections from the Da River basin in Phong Tho district, Lai Chau province. Pareuchiloglanis sp. can be distinguished from congeners by the following unique combination of characters: D. i,6; A. i,4; P1. i,14-16 (primarily i,16); C. i,6-8,6-8,i (primarily i,8,8,i); interorbital distance\eye diameter 2.4-3.4; caudal peduncle length 17.1-21.5; caudal pedunle depth 6.0-7.0% SL; length of adipose base\dorsal to adipose distance averaged 1.8; head length 19.2-24.3; anal-fin origin closer to the anus than to the caudal-fin base; adipose-fin base posterior to the tip of pelvic-fin rays; the pelvic-fin insertion located opposite to the fourth dorsal fin-ray element; maxillary barbel extending just beyond base of first pectoral-fin element; and yellow patches on dorsal surface (a broader pair on the last doral-fin ray, as large as two thirds length of pelvic-fin). Morphological analysis showed that Pareuchiloglanis sp. are closed to two species in the same surveyed area, P. tamduongensis and P. songdaensis. This paper also indicated morphological differences between Pareuchiloglanis sp. and other species that have yellow patches on dorsal surface. This species record implied the potential of biodiversity of Pareuchiloglanis in the headwaters of the Red River. These findings provide worthy data for further studies on taxonomy of this genus in northern Vietnam.

A new species of South America marsh rat (Holochilus, Cricetidae) from northeastern Brazil

AbstractMarsh rats of the genus Holochilus are broadly distributed and inhabit several distinct environments throughout South America. As an enigmatic group with a somewhat uncertain taxonomy, the composition and names of taxa have shifted throughout history, including the boundaries of Holochilus sciureus, a species formerly distributed in the lowlands of the Guianas, Peru, Bolivia, and northern, central, and northeastern of Brazil. Based on a combination of morphological and morphometric traits, and genomic sequences, we redefined species boundaries and split this wide concept of H. sciureus into three separated species, including a redefined H. sciureus, the newly erected from synonymy H. nanus, and an unnamed taxon. We describe this unnamed species, and provide emended diagnoses for the two redefined species. The newly named taxon inhabits the northeastern part of Brazil and differs from the other congeners by a unique combination of phenotypic and genomic characters.

Re-description of the sexually dimorphic peltopleuriform fish Wushaichthys exquisitus (Middle Triassic, China): taxonomic implications and phylogenetic relationships

Wushaichthys exquisitus, a small fish from the Ladinian of Xingyi, Guizhou Province, southern China, was named a few years ago and interpreted as the most primitive species in the Thoracopteridae (Triassic ‘flying’ fishes with a Euro-Asian distribution). However, this hypothesis was questioned, because Wushaichthys also shares features with Peltopleuridae. A detailed morphological re-description of Wushaichthys was conducted based on new specimens, plus a revision of previously studied ones, as well as of members of Peripeltopleurus and thoracopterids, and their relationships were tested with a phylogenetic analysis based on 137 characters and 54 taxa. The results suggest that Wushaichthys is a member of a clade that is interpreted here as the new superfamily Thoracopteroidea, which contains Wushaichthyidae fam. nov. (Wushaichthys + Peripeltopleurus) and Thoracopteridae and is the sister taxon of the non-monophyletic Peltopleuridae among Peltopleuriformes. Thoracopteroidea superfam. nov. is strongly supported by numerous synapomorphies (e.g. frontal (= parietal) bone slightly expanded laterally; posttemporal contacts the extrascapular anterolaterally separating it from its counterpart; suspensorium is vertically oriented; narrow and deep rectangular preopercle, vertically oriented; preopercle sutured with the rear edge of the maxilla throughout the maxillary process; enlarged pectoral fins in most genera; and deeply forked hypocercal caudal fin). Although Thoracopteridae is monophyletic, one of its genera, Thoracopterus, is not. Consequently, the content of Thoracopteridae was re-evaluated and now includes Thoracopterus, Gigantopterus, Potanichthys comb. nov. and Italopterus gen. nov. Wushaichthyidae is supported by a unique combination of characters, and the results confirm it as a thoracopteroid, but not a thoracopterid. The characters of Wushaichthys are relevant for understanding the taxonomy and systematics of thoracopteroids, especially the evolutionary morphological modifications of the pectoral and pelvic fins and the lower lobe of the caudal fin, which are some of the main characters of these fishes. http://zoobank.org/urn:lsid:zoobank.org:pub:8FFF4E8D-780C-4DFB-B0C8-7E27D912CE8E

Pseudomataeopsephus, a new genus of water penny beetles from mid-Cretaceous Burmese amber (Coleoptera: Psephenidae)

Mesozoic fossils of Psephenidae are sparse. Here we characterise, describe and figure a new genus and species of Psephenidae from the Albian/Cenomanian Burmese amber, Pseudomataeopsephus burmensis gen. et sp. nov, based on an adult male. Pseudomataeopsephus has an interesting combination of characters, including filiform antennae in male, pronotum with crenulate basal rim, scutellum and elytra with smooth basal rims, mesoventral process with emarginate apex, and abdomen with five ventrites. This unique character combination is unknown in any extant psephenid subfamilies, suggesting that Pseudomataeopsephus may represent an early-diverging lineage in Psephenidae.

Rise of Subgen. Rhoicosphenula Lange-Bert. to the Genus Level, and Description of a New Gomphosphenia s.s. Species from Puerto Rico

The subgenus Rhoicosphenula Lange-Bert. has a unique character combination that differentiates it from Gomphosphenia subgen. Gomphosphenia Lange-Bert. In particular, Rhoicosphenula has striae/areola features that are similar to Gomphosphenia, but is differentiated from that genus by also having pseudosepta present on both poles of the valves, copulae with septa at one of the poles, and frustules almost rectangular in girdle view. Together, this character combination strongly supports it as an independent genus following modern diatom-taxonomy criteria. Moreover, the only species of Rhoicosphenula known so far was collected from a peculiar acidic and dystrophic habitat, whilst most Gomphosphenia s.s. species colonize medium-conductivity, alkaline inland waters. On the basis of LM and SEM studies, we also propose a species of Gomphosphenia (G. patrickiana Cantonati, Lange-Bert., Kociolek & A.A.Saber, sp. nov.) as new to science. The new species is mainly defined by its valve outline and dimensions, length to breadth ratio, striation density, and geographical distribution. It was found in several samples of two streams in Puerto Rico, sometimes with high relative abundance. Gomphosphenia patrickiana Cantonati, Lange-Bert., Kociolek & A.A.Saber, sp. nov. was much more abundant in the stream with lower nutrient (in particular P) concentrations, and higher ecological integrity. The new species seems to prefer moderately alkaline freshwater habitats with medium-high conductivity and oligo- to mesotrophic conditions, with moderate tolerance to N enrichment. Also noteworthy is the occurrence of the new species in streams with above-average magnesium concentrations (due to the local geology). This Neotropical, warm-water species might be a potential indicator of global warming effects.

Long-headed predators in Cretaceous amber—fossil findings of an unusual type of lacewing larva

Lacewing larvae (Neuroptera) are known to be fierce predators which are morphologically highly specialised for a raptorial lifestyle. Mandibular-maxillary stylets are characteristic for all larvae of this group; these stylets can be extraordinarily massive. Despite these distinct sucking-piercing stylets, also other extreme features occur in some ingroups, such as an extremely elongated neck. In larvae of thread-winged lacewings (Crocinae) the neck can reach up to about one third of the body length; they are also called ‘long-necked antlions’. Even though the larvae of living neuropteran species show a variety of conspicuous morphologies today, indeed 100 million years ago, in the Cretaceous, Neuroptera seems to have had an even more “experimental phase”. Several larval specimens are known so far especially in Myanmar, Spanish and Lebanese amber from the Cretaceous with unique and unusual character combinations not found in any group living today. We describe here ten new fossil findings of one of these types of larvae with elongated head capsule in Myanmar amber, previously only known from a single specimen. We compared the head shapes of the new specimens with those of 190 specimens of other lacewing larvae and discuss further implications of our findings, especially making functional comparisons with long-necked antlions.

Description and revised diagnosis of Asia’s first recorded pachycephalosaurid, Sinocephale bexelli gen. nov., from the Upper Cretaceous of Inner Mongolia, China

The first recorded pachycephalosaurid dinosaur from outside of North America, “Troodon” bexelli, was described from the Upper Cretaceous of Nei Mongol (Inner Mongolia) Autonomous Region, China, in 1953 based on a partial parietal dome. The holotype, and only, specimen has not been redescribed or figured since the original description and is currently considered lost. As a result, researchers have generally considered this taxon a nomen dubium. Here, we identify and describe two high-fidelity plaster casts of the holotype and assign them as plastotypes for this taxon. Examining these replicas allows for an updated comparative description and complete systematic revision of this enigmatic taxon and its inclusion within a phylogenetic analysis for the first time. The material is distinct from all other pachycephalosaur material and can be diagnosed by a single autapomorphy (a wide and deeply embayed posterior parietal margin) and a unique combination of characters, including lack of primary nodes on the parietal and a highly arched, fully roofed temporal chamber. A new genus, Sinocephale gen. nov. is established to receive this species as Sinocephale bexelli. Sinocephale bexelli is phylogenetically removed from Stegoceras (formerly “Troodon”), to which it was previously affiliated, and recovered as a pachycephalosaurine pachycephalosaurid.