Thursday, December 31, 2020

[Ornithology • 2021] Genus Epinecrophylla • Systematics of A Neotropical Clade of Dead-leaf-foraging Antwrens (Aves: Thamnophilidae)

Epinecrophylla spp.

in Johnson, Howard & Brumfield, 2021. 

• Comprehensive taxon and population-level sampling for thousands of genetic markers.
• Well-resolved phylogeny for the group.
• Three broadly sympatric Amazonian species complexes.
• Paraphyly at the species and subspecies levels.

The stipple-throated antwrens of the genus Epinecrophylla (Aves: Thamnophilidae) are represented by eight species primarily found in the lowlands of the Amazon Basin and the Guiana Shield. The genus has a long and convoluted taxonomic history, with many attempts made to address the taxonomy and systematics of the group. Here we employ massively parallel sequencing of thousands of ultraconserved elements (UCEs) to provide both the most comprehensive subspecies-level phylogeny of Epinecrophylla antwrens and the first population-level genetic analyses for most species in the genus. Most of our results are robust to a diversity of phylogenetic and population genetic methods, but we show that even with thousands of loci we are unable to fully resolve the relationships between some western Amazonian species in the haematonota group. We uncovered phylogenetic relationships between taxa and patterns of population structure that are discordant with both morphology and current taxonomy. For example, we found deep genetic breaks between taxa in the ornata group that are currently regarded as species, and in the haematonota and leucophthalma groups we found paraphyly at the species and subspecies levels, respectively. As has been found in many Amazonian taxa, our phylogenetic results show that the major river systems of the Amazon Basin appear to have an effect on the genetic structure and range limits within Epinecrophylla. Our population genetics analyses showed extensive admixture between some taxa despite their deep genetic divergence. We present a revised taxonomy for the group and suggest areas for further study.
 Keywords: Systematics, Ultraconserved elements, Phylogenomics, Epinecrophylla, Amazonia


 Oscar Johnson, Jeffrey T. Howard and Robb T. Brumfield. 2021. Systematics of A Neotropical Clade of Dead-leaf-foraging Antwrens (Aves: Thamnophilidae; Epinecrophylla). Molecular Phylogenetics and Evolution. 154, 106962. DOI: 10.1016/j.ympev.2020.106962

[Ichthyology • 2020] Microcambeva bendego • A New Catfish Species of Microcambeva Costa & Bockmann 1994 (Siluriformes: Trichomycteridae) from A Coastal Basin in Rio de Janeiro State, southeastern Brazil

Microcambeva bendego
de Medeiros, Moreira, de Pinna & Lima, 2020

Microcambeva bendego, a small psammophilous catfish species, is described from the rio Guapi-Macacu basin at Guanabara Bay in Rio de Janeiro State, an Atlantic Forest remnant. This coastal drainage has been explored by several naturalists and fish researchers since the 19th century. It is a drainage with remarkably high endemism and species richness, and some recently-described and threatened species. The new species is distinguished from all congeners by two distinctive characters: long finger-like projections in the branchial isthmus and a large opercular patch of odontodes with 19 odontodes. Due to the paucity of specimens (n=3) osteological features of the new species were accessed by CT-Scan images of the holotype. Microcambeva bendego shares putative synapomorphies with two congeners, M. ribeirae and M. filamentosa, such as the fusion of supraorbital pore s6, the absence of ossification in the anterior autopalatine cartilage, the presence of an elongated and wide posterior process of the autopalatine, and a concavity on the dorsal process of the opercle. Those characters suggest that M. bendego is more closely related to those two species from the rio Ribeira de Iguape basin than to other congeners. The biogeography and conservation status of M. bendego are also discussed.

Keywords: Pisces, Taxonomy, Microcambevinae, Fluminense ecoregion, Atlantic Forest, Guanabara bay, CT-Scan

Figure 1. Microcambeva bendego, new species, holotype, MNRJ 52042, 28.1 mm SL.
Rio Guapiaçu, near Cachoeiras de Macacu, rio Guapi-Macacu basin, Guapimirim Municipality, Rio de Janeiro State, southeastern Brazil.
a. lateral view; b. dorsal view; c. ventral view. Scale: 10 mm.

Figure 2. Ventral view of holotype of Microcambeva bendego, new species, holotype, MNRJ 52042, 28.1 mm SL, white arrow indicates the finger-like projections. Scale bar: 1.0mm.

Lucas Silva de Medeiros, Cristiano Rangel Moreira, Mario de Pinna and Sergio M. Q. Lima. 2020. A New Catfish Species of Microcambeva Costa & Bockmann 1994 (Siluriformes: Trichomycteridae) from A Coastal Basin in Rio de Janeiro State, southeastern Brazil. Zootaxa. 4895(1); 111–123. DOI: 10.11646/zootaxa.4895.1.6

[Botany • 2020] Primulina elegans (Gesneriaceae) • A New Species from North Vietnam

Primulina elegans B. M. Wang, Y. H. Tong & N. H. Xia

in Tong, Wang, et al., 2020. 
DOI: 10.1111/njb.02942   

Primulina elegans (Gesneriaceae), a new species from Vietnam is described. This species is similar to P. gemella and P. diffusa in having stolons and papillose‐hispid leaves, but is easily distinguished from them by having 9–15 cymes and corollas with two brown stripes on the adaxial lip and nine purplish lines on the abaxial lip. Furthermore, Primulina elegans differs from P. gemmella by its broadly infundibuliform corollas with purplish glandular pubescent filaments, and from P. diffusa by having three slightly purplish glandular pubescent staminodes.

Keywords: Gesneriaceae, new species, Primulina, Vietnam

Primulina elegans B. M. Wang, Y. H. Tong & N. H. Xia sp. nov. 
Etymology: The species epithet refers to its beautiful flowers, which gives this species a high ornamental value.

Yi‐Hua Tong, Bing‐Mou Wang, Tien Chinh Vu and Nian‐He Xia. 2020. Primulina elegans (Gesneriaceae), A New Species from North Vietnam. Nordic Journal of Botany. DOI: 10.1111/njb.02942 

[Herpetology • 2020] Leptotyphlops sylvicolus Broadley & Wallach, 1997 One Species hides Many: Molecular and Morphological Evidence for Cryptic Speciation in A Thread Snake (Serpentes: Leptotyphlopidae)


 Leptotyphlops sylvicolus Broadley & Wallach, 1997

in Busschau, Conradie & Daniels. 2020. 

We investigate the phylogeographic structure of a fossorial forest‐living snake species, the forest thread snake, Leptotyphlops sylvicolus Broadley & Wallach, 1997 by sampling specimens from the Eastern Cape and KwaZulu‐Natal provinces of South Africa. Phylogenetic results, using Bayesian inferences and maximum likelihood, from the combined mitochondrial sequence data (cyt b and ND4), along with population genetic analyses suggest the presence of phylogeographic breaks broadly congruent to those exhibited by other forest‐living taxa. Divergence‐time estimates indicate that cladogenesis within the study taxon occurred during the late Miocene climatic shifts, suggesting that cladogenesis was driven by habitat fragmentation. We further investigate the species‐level divergence within L. sylvicolus by including two partial nuclear loci (PRLR and RAG1). The three species delimitation methods (ABGD, bGMYC, and STACEY), retrieved 10–12 putative species nested within the L. sylvicolus species complex. These results were corroborated by iBPP implementing molecular and morphological data in an integrative Bayesian framework. The morphological analyses exhibit large overlap among putative species but indicate differences between grassland and forest species. Due to the narrow distributions of these putative species, the results of the present study have further implications for the conservation status of the L. sylvicolus species complex and suggest that forest and grassland habitats along the east coast of South Africa may harbor significantly higher levels of diversity than currently recognized.

Theo Busschau, Werner Conradie and Savel R. Daniels. 2020. One Species hides Many: Molecular and Morphological Evidence for Cryptic Speciation in A Thread Snake (Leptotyphlopidae: Leptotyphlops sylvicolus Broadley & Wallach, 1997).  Journal of Zoological Systematics and Evolutionary Research. DOI: 10.1111/jzs.12401

We investigated the phylogeographic structure of a fossorial forest‐living snake species, Leptotyphlops sylvicolus. Phylogenetic and population genetic analyses suggest the presence of phylogeographic breaks broadly congruent to those exhibited by other forest‐living taxa. Divergence‐time estimates suggest that cladogenesis was driven by habitat fragmentation during the late Miocene climatic shifts. The species delimitation methods retrieved 10–12 putative species nested within L. sylvicolus. Morphological analyses exhibit large overlap among putative species but indicate differences between grassland and forest species.


[Botany • 2020] Zingiber porphyrochilum (Zingiberaceae) • A New Species from Yunnan, China

 Zingiber porphyrochilum Y.H.Tan & H.B.Ding

in Ding, Yang, Lu et Tan, 2020. 
紫唇姜 || DOI: 10.5735/085.057.0401 

Zingiber porphyrochilum Y.H. Tan & H.B. Ding sp. nova (Zingiberaceae) from Yunnan, China is described and illustrated. It is similar to Z. densissimum in its bilobed ligule and flower shape but differs from it by having a longer clumped pseudostem (1.5–2.5 m tall vs. solitary, 0.4–0.7 m tall), longer ligules (3–11 mm long vs. ca. 3 mm long), brownish yellow corolla lobes (vs. pure white), labellum and lateral staminodes brownish yellow at the base, and bright clear red to dark purplish towards the apex and margins (vs. pure white).

 Zingiber porphyrochilum Y.H.Tan & H.B.Ding

Hong-Bo Ding, Bin Yang, Xiao-Qiang Lu and Yun-Hong Tan. 2020. Zingiber porphyrochilum (Zingiberaceae), A New Species from Yunnan, China. Annales Botanici Fennici. 57(4-6); 197-201. DOI: 10.5735/085.057.0401 


[Herpetology • 2019] Kladirostratus gen. nov. & Psammophylax kellyi A Snake in the Grass: Genetic Structuring of the Widespread African Grass Snake (Psammophylax Fitzinger 1843), with the Description of A New Genus and A New Species


 Kladirostratus acutus (Günther 1888) 

in Keates, Conradie, Greenbaum & Edwards, 2019. 

Psammophylax (Fitzinger 1843) is a widespread yet poorly studied genus of African grass snakes. A genetic phylogeny of six of the seven species was estimated using multiple phylogenetic and distance‐based methods. To support the genetic analyses, we conducted morphological analyses on the body (traditional morphology) and head (geometric morphometrics) separately. Phylogenetic analyses recovered a similar topology to past studies, but with better resolution and node support. We found substantial genetic structuring within the genus, supported by significantly different head shapes between P. a. acutus and other Psammophylax . Psammophylax a. acutus was recovered as sister to its congeners, and sequence divergence values and morphometrics supported its recognition as a new genus. Increased sampling in East Africa (Tanzania, Kenya, and Ethiopia) revealed that Psammophylax multisquamis is polyphyletic, necessitating the description of a new, morphologically cryptic species from northern Tanzania. The distribution of P. multisquamis sensu stricto is likely restricted to Kenya and Ethiopia. The study has further resolved multiple aspects of Psammophylax systematics, including the taxonomic validity of two central African subspecies, P. variabilis vanoyei (Laurent 1956) and P. tritaeniatus subniger (Laurent 1956). Inclusion of specimens from the more remote parts of Africa, in future analyses, may result in the recovery of additional diversity within Psammophylax .

Keywords: geometric morphometrics, grass snake, molecular biology, phylogenetic analysis, Psammophiinae, taxonomy

Kladirostratus acutus comb. nov. 

 Kladirostratus acutus (Günther 1888) 

Kladirostratus gen. nov. Conradie, Keates & Edwards 
Proposed common group name: Branch's Beaked Snakes.

Type species: Psammophis acutus Günther 1888.

Etymology: The name Kladirostratus is derived from the combination of the Greek word κλάδος (klados) meaning “branch,” and the Latin word “rostratus” meaning beaked. The name honors Professor William R. Branch (1947–2018), Curator Emeritus of herpetology at Port Elizabeth Museum, in recognition of his many contributions to the herpetology of Africa, especially regarding snakes. We benefitted from his generosity as a mentor and he helped shape our careers, for which we are thankful. The name is masculine in gender.

Members of this genus: Kladirostratus acutus (Günther 1888) comb. nov. including the currently recognized subspecies Kladirostratus a. acutus and Kladirostratus a. jappi (Broadley, 1971); Kladirostratus togoensis (Matschie 1893) comb. nov. The latter is provisionally included in this genus based on morphological similarities, but this requires confirmation through molecular phylogenetic analysis.

Distribution: Kladirostratus a. acutus comb. nov. is known from most of Angola through northwestern Zambia, southern Democratic Republic of the Congo (DRC), into western Tanzania, northern Malawi, and north to Rwanda (fide Broadley, 1971). Kladirostratus a. jappi comb. nov. is known only from western Zambia and northeastern Angola (fide Broadley, 1971). Kladirostratus togoensis comb. nov. is known from Ghana, Togo, Central African Republic, northern DRC, and western Uganda (fide Broadley, 1971; Spawls et al., 2002). Occurs at elevations of 450–1,800 m.

Psammophylax kellyi sp. nov.

 Psammophylax kellyi sp. nov. Conradie, Keates & Edwards  
Proposed common name: Tanzanian Grass Snake or Tanzanian Skaapsteker.

Etymology. The specific epithet is a patronym in honor of Christopher M. R. Kelly for his considerable contribution to the systematics of the snake family Lamprophiidae.

Chad Keates, Werner Conradie, Eli Greenbaum and Shelley Edwards. 2019. A Snake in the Grass: Genetic Structuring of the Widespread African Grass Snake (Psammophylax Fitzinger 1843), with the Description of A New Genus and A New Species. Journal of Zoological Systematics and Evolutionary Research.  57(4); 1039-1066.  DOI: 10.1111/jzs.12337 

Eastern Cape researchers discover new snake species

[Entomology • 2020] Description of the Male of Tanyxiphium harriet (Hymenoptera: Mymaridae), with New Distribution Records and Synonymy

Tanyxiphium harriet Zeya 2015  

in Triapitsyn, Aishan & Huber, 2020.


Tanyxiphium longissimum Huber, syn. n. (Hymenoptera: Mymaridae) is synonymized under T. harriet (Zeya) based on examination of specimens from Hainan Island and Yunnan Province in the Oriental part of China, Sulawesi Island in Indonesia, Peninsular Malaysia, and Thailand. These are new country distribution records except for Thailand. The previously unknown male of T. harriet is described from Sulawesi Island, and the female is redescribed and illustrated based on non-type material examined.

Keywords: Hymenoptera, Chalcidoidea, fairyfly, Gonatocerini, taxonomy, Oriental region

Tanyxiphium harriet Zeya 2015

Serguei V. Triapitsyn, Zhulidezi Aishan and John T. Huber. 2020. Description of the Male of Tanyxiphium harriet (Hymenoptera: Mymaridae), with New Distribution Records and Synonymy. Zootaxa. 4896(1);105–112. DOI: 10.11646/zootaxa.4896.1.5

[Crustacea • 2020] New Records of Two Sponge-associated Species of Upogebia Leach, 1814 (Decapoda: Gebiidea: Upogebiidae) from southern India: U. hexaceras and U. nithyanandan resurrected from the synonymy of U. balmaorum

Upogebia nithyanandan (Sakai, Türkay & Al Aidaroos, 2015)

in Komai, Ravinesh, Riyas & Kumar, 2020.


Two species of the mud shrimp genus Upogebia Leach, 1814 (Gebiidea: Upogebiidae) are recorded from India for the first time based on material from Tamil Nadu: U. hexaceras (Ortmann, 1894) and U. nithyanandan (Sakai, Türkay & Al Aidaroos, 2015). Both were found in burrows in an unidentified sponge. Upogebia nithyanandan is resurrected as a valid species from the synonymy of U. balmaorum Ngoc-Ho, 1990, recently proposed by Dworschak & Poore (2018). The two species are fully described and illustrated on the basis of the newly collected specimens, and diagnostic characters for species recognition are discussed.

Keywords: Decapoda, Kuwaitupogebia, synonymy, Tamil Nadu

Upogebia nithyanandan (Sakai, Türkay & Al Aidaroos, 2015).
Living specimen (male cl 4.3 mm; DABFUK/ AR-AN 111) inhabiting burrow in an unidentified sponge.

Tomoyuki Komai, Raveendhiran Ravinesh, Abdul Riyas and Appukuttannair Biju Kumar. 2020. New Records of Two Sponge-associated Species of Upogebia Leach, 1814 from southern India (Decapoda: Gebiidea: Upogebiidae): U. hexaceras (Ortmann, 1894) and U. nithyanandan (Sakai, Türkay & Al Aidaroos, 2015) resurrected from the synonymy of U. balmaorum Ngoc-Ho, 1990. Zootaxa. 4747(3); 477–494. DOI: 10.11646/zootaxa.4747.3.3

[Fungi • 2020] Amended Description of the rarely reported Bryophilous Ascomycete Octospora svrcekii (Pyronemataceae) with Notes on the Phylogeny of the Section Wrightoideae

 Octospora svrcekii Benkert (1998)

in Sochorová, Matočec, Kušan, et al., 2020.
The bryophilous ascomycete Octospora svrcekii, belonging to the section Wrightoideae, has so far been reported from only three localities in the world. New collections from Albania, Austria, Croatia, France, Slovakia and Spain have enabled a better understanding of its variability, ecology, distribution and phylogenetic relationships with other taxa within the section Wrightoideae. Octospora svrcekii was always found associated with Cratoneuron filicinum growing in constantly humid habitats (brooks, rivers or waterfalls), on calcareous bedrock. A species description based on both living and dead material is provided and compared with previous observations. A phylogenetic analysis of the section Wrightoideae, performed using the EF1α, SSU rDNA and LSU rDNA loci, revealed that Octospora svrcekii forms a monophyletic group with O. wrightii, O. erzbergeri, O. hygrohypnophila and O. americana, all of which are characterised by subglobose to broadly ellipsoid ascospores ornamented with isolated warts, and infect mosses in the order Hypnales, inducing galls on their rhizoids. Based on the molecular analysis, O. orthotrichi and O. affinis, formerly also considered as members of the section Wrightoideae, do not belong to the group.

Keywords: Bryophilous fungi, fungal systematics, galls, pleurocarpous mosses, vital taxonomy, Fungi

Zuzana Sochorová, Neven Matočec, Ivana Kušan, Lukáš Janošík, Jan Eckstein, Marcel Vega, Armin Mešić, Michaela Sedlářová, Rubén Martínez-Gil and Michal Sochor. 2020. Amended Description of the rarely reported Bryophilous Ascomycete Octospora svrcekii (Pyronemataceae) with Notes on the Phylogeny of the Section WrightoideaePhytotaxa. 475(1); 1–17. DOI: 10.11646/phytotaxa.475.1.1

Wednesday, December 30, 2020

[Paleontology • 2021] An Oviraptorid Preserved Atop An Embryo-bearing Egg Clutch sheds light on the Reproductive Biology of Non-avialan Theropod Dinosaurs

 an oviraptorid specimen [LDNHMF2008]
consisting of an adult skeleton preserved atop an embryo-bearing egg clutch. 

Bi, Amiot, Peyre de Fabrègues, ... et Xu, 2020.
 Artwork by Zhao Chuang.

Recent studies demonstrate that many avialan features evolved incrementally prior to the origin of the group, but the presence of some of these features, such as bird-like brooding behaviours, remains contentious, in non-avialan dinosaurs. Here we report the first non-avialan dinosaur fossil known to preserve an adult skeleton atop an egg clutch that contains embryonic remains. The preserved positional relationship of the adult to the clutch, coupled with the advanced growth stages of the embryos and their high estimated incubation temperatures, provides strong support for the brooding hypothesis. Furthermore, embryos in the clutch are at different developmental stages, suggesting the presence of asynchronous hatching—a derived feature even among crown-group birds—in non-avialan theropods. These findings demonstrate that the evolution of reproductive biology along bird-line archosaurs was a complex rather than a linear and incremental process, and suggest that some aspects of non-avialan theropod reproduction were unique to these dinosaurs.

Keywords: Oviraptorosauria, Cretaceous, Clutch, Brooding, Embryos, Asynchronous hatching

Fig. 1. LDNHMF2008, an oviraptorid specimen consisting of an adult skeleton preserved atop an embryo-bearing egg clutch.
(a) Photograph. (b) Interpretive drawing with bones and gastroliths in white and eggs color-coded by ring (A, red; B, green; C, blue).
(c) Restoration (white indicates bones preserved in the adult skeleton).

Abbreviations: I, digit I; II, digit II; III, digit III; A#, egg in lowermost ring (A); as, astragalus; B#, egg in middle ring (B); C#, egg in uppermost ring (C); cav, caudal vertebra; ch, chevron; cv, cervical vertebra; di, manual digit; dr, dorsal ribs; dv, dorsal vertebra; em, egg known to preserve embryo; fe, femur; fi. fibula; ga, gastralium; gl, gastroliths; h, humerus; il, ilium; is, ischium; mt, metatarsal; O2, egg sampled for oxygen isotope analysis; pb, pubis; pp, pedal phalanges; ra, radius; sl, semilunate carpal; ti, tibia; ul, ulna. Note that C11 and C12 are not paired eggs. The eggs that would have been paired with C11 and C12 are probably not preserved, as is the case for some other eggs and skeletal elements.

An attentive oviraptorid theropod dinosaur broods its nest of blue-green eggs while its mate looks on in what is now Jiangxi Province of southern China some 70 million years ago.
 Artwork by Zhao Chuang.

 Shundong Bi, Romain Amiot, Claire Peyre de Fabrègues, Michael Pittman, Matthew C. Lamanna, Yilun Yu, Congyu Yu, Tzuruei Yang, Shukang Zhang, Qi Zhao and Xing Xu. 2020. An Oviraptorid Preserved Atop An Embryo-bearing Egg Clutch sheds light on the Reproductive Biology of Non-avialan Theropod Dinosaurs. Science Bulletin. In Press. DOI: 10.1016/j.scib.2020.12.018

Researchers Announce World’s First Dinosaur Preserved Sitting on Nest of Eggs that Includes Fossilized Babies

Tuesday, December 29, 2020

[Ichthyology • 2020] Nemipterus elaine • A New Species of Nemipterus (Pisces: Nemipteridae) from the Western Indian Ocean

Nemipterus elaine
 Russell & Gouws, 2020

A new species of threadfin bream, Nemipterus elaine, from the Western Indian Ocean is described. The new species is known so far only from off the coast of southern Mozambique, and appears most closely related morphologically and genetically to N. randalli Russell, 1986, but differs in having shorter pectoral and pelvic fins, and the upper caudal lobe produced to form a short, bright yellow filament (a long red trailing filament present in N. randalli). A key to the species of Nemipterus in the Western Indian Ocean is provided.

Keywords: Pisces, Nemipteridae, Nemipterus elaine n.sp., Mozambique, Western Indian Ocean

Nemipterus elaine

Barry C. Russell and Gavin Gouws. 2020. A New Species of Nemipterus (Pisces: Nemipteridae) from the Western Indian Ocean. Zootaxa. 4895(4); 573–580. DOI: 10.11646/zootaxa.4895.4.7

[Paleontology • 2020] Paludirex gen. nov. • Australia’s Prehistoric ‘Swamp King’: Revision of the Plio-Pleistocene Crocodylian Genus Pallimnarchus de Vis, 1886 (Crocodylidae: Mekosuchinae)

Paludirex vincenti 
Ristevski, Yates, Price, Molnar, Weisbecker & Salisbury, 2020

The crocodylian fossil record from the Cenozoic of Australasia is notable for its rich taxonomic diversity, and is primarily represented by members of the clade Mekosuchinae. Reports of crocodylian fossils from Australia date back to the late nineteenth century. In 1886, Charles Walter de Vis proposed the name Pallimnarchus pollens for crocodylian fossils from southeast Queensland—the first binomen given to an extinct crocodylian taxon from Australia. Pallimnarchus has come to be regarded as a large, broad-snouted crocodylian from Australia’s Plio-Pleistocene, and numerous specimens, few of which are sufficiently complete, have been assigned to it by several authors throughout the twentieth century. In the late 1990s, the genus was expanded to include a second species, Pallimnarchus gracilis. Unfortunately, the original syntype series described as Pallimnarchus pollens is very fragmentary and derives from more than one taxon, while a large part of the subsequently selected lectotype specimen is missing. Because descriptions and illustrations of the complete lectotype do not reveal any autapomorphic features, we propose that Pallimnarchus pollens should be regarded as a nomen dubium. Following this decision, the fossil material previously referred to Pallimnarchus is of uncertain taxonomic placement. A partial skull, formerly assigned to Pallimnarchus pollens and known as ‘Geoff Vincent’s specimen’, possesses many features of diagnostic value and is therefore used as basis to erect a new genus and species—Paludirex vincenti gen. et sp. nov. A comprehensive description is given for the osteology of ‘Geoff Vincent’s specimen’ as well as aspects of its palaeoneurology, the latter being a first for an extinct Australian crocodyliform. The newly named genus is characterized by a unique combination of premaxillary features such as a distinctive arching of the anterior alveolar processes of the premaxillae, a peculiar arrangement of the first two premaxillary alveoli and a large size disparity between the 3rd and 4th premaxillary alveoli. These features presently allow formal recognition of two species within the genus, Paludirex vincenti and Paludirex gracilis comb. nov., with the former having comparatively more robust rostral proportions than the latter. The Paludirex vincenti holotype comes from the Pliocene Chinchilla Sand of the Darling Downs, south-eastern Queensland, whereas the material assigned to Paludirex gracilis is from the Pleistocene of Terrace Site Local Fauna, Riversleigh, northwest Queensland. Phylogenetic analyses recover Paludirex vincenti as a mekosuchine, although further cladistic assessments are needed to better understand the relationships within the clade.

Figure 7: Paludirex vincenti gen. et sp. nov., ‘Geoff Vincent’s specimen’ (CMC2019-010 + QMF59017), holotype, all skull pieces in dorsal view. (A) Non-annotated photograph, and (B) annotated photograph. The arrow in (A) points to a clearer view of the basicranium (QMF59017) from its approximate anatomical position ventral to the cranial table (CMC2019-010-5). The dashed lines in (B) highlight the hypothetical outline of the skull.
Abbreviations: bo, basioccipital; bs, basisphenoid; fro, frontal; jug, jugal; lac, lacrimal; max, maxilla; nas, nasals; oto, otoccipital; par, parietal; pmx, premaxilla; po, postorbital; prf, prefrontal; q, quadrate; qj, quadratojugal; sq, squamosal.

Figure 8: Paludirex vincenti gen. et sp. nov., ‘Geoff Vincent’s specimen’ (CMC2019-010 + QMF59017), holotype—specimen background.
(A) and (B) ‘Geoff Vincent’s specimen’ as photographed at Mr. Vincent’s house, and (C) the specimen as photographed on display at the Queensland Museum sometime in the 1990s. Several pieces are missing in B (also in A, albeit less apparent), specifically, the posterior portion of the left maxilla (from CMC2019-010-4); the cranial table unit (CMC2019-010-5) is missing its right half; and, the quadratojugal & posterior jugal process unit (CMC2019-010-7). The reason why these pieces are not in the photographs is unknown, as they are obviously present in (C) when the specimen was publicly displayed. Also notice a small unidentified piece glued posteriorly to the lacrimal (B) that is not depicted in the display mount (C) and could not be located with the specimen as examined for the purposes of this study. Photographs in (A) and (B) taken August 1988 by Ralph E. Molnar; photograph in (C) property of the Chinchilla Museum, used with permission.

Figure 39: Hypothetical size reconstruction silhouette of Paludirex vincenti gen. et sp. nov.
The skull shape reconstruction is based on the Paludirex vincenti holotype (‘Geoff Vincent’s specimen’ CMC2019-010 + QMF59017). The hypothetical body outline and proportions of Paludirex vincenti are based on those of extant crocodylians. The osteoderms are intentionally not depicted since the osteoderm configuration is currently unknown for Paludirex vincenti. The human (dark gray silhouette on the left) is 1.80 m tall.

Systematic Paleontology
CROCODYLOMORPHA Hay, 1930 (sensu Nesbitt, 2011)
CROCODYLIFORMES Hay, 1930 (sensu Sereno et al., 2001)
MESOEUCROCODYLIA Whetstone & Whybrow, 1983 (sensu Sereno et al., 2001)

EUSUCHIA Huxley, 1875
CROCODYLIA Gmelin, 1789 (sensu Benton & Clark, 1988)
CROCODYLOIDEA Fitzinger, 1826 (sensu Brochu, 2003)
MEKOSUCHINAE (Balouet & Buffetaut, 1987)

Type species— Paludirex vincenti gen. et sp. nov.

Etymology— The generic name is from the Latin paludis and rex, meaning ‘swamp king’. This roughly preserves the original meaning of Pallimnarchus which is a Greek contraction with the meaning ‘ruler of all the swamps’.

Generic diagnosis— Large-bodied mekosuchine crocodyloids (capable of attaining a TL of at least 4 m at maturity) with proportionately broad snouts characterized by the following unique combination of features: (1) dorsally arched premaxillary alveolar processes at the level of the first two alveoli; (2) anterior profile of the premaxilla in lateral view is shallowly sloping; (3) premaxillary alveoli with circular to sub-circular outlines; (4) 1st and 2nd premaxillary alveoli approximately in line with each other, and separated by substantial interalveolar spaces more so than the other premaxillary alveoli; (5) large 4th premaxillary alveolus with a circumference 1.5 to 2 times greater than the 3rd premaxillary alveolus.


Etymology— The specific epithet honors the late Mr. Geoff Vincent, discoverer of the holotype specimen.

Holotype— ‘Geoff Vincent’s specimen’ (CMC2019-010 + QMF59017), partial skull.

Type locality and horizon— A property adjacent to the Chinchilla Riffle Range, Darling Downs, south-eastern Queensland; Chinchilla Sand deposits, Chinchilla Local Fauna, age Pliocene, Neogene.

Referred specimen— QMF11626, left premaxilla and partial maxilla, found along the Condamine River near Warra; age uncertain.

Pallimnarchus pollens is herein regarded a nomen dubium since its designated lectotype specimen is almost completely missing and, based on its published descriptions and illustrations, deemed to be non-diagnostic. Following this verdict, the majority of fossil specimens formerly assigned to Pallimnarchus are temporarily of undetermined generic and specific placement. Only a handful of the examined specimens previously referred to Pallimnarchus were sufficiently preserved to allow the establishment of a new crocodylian genus, Paludirex. As currently understood, the genus Paludirex consists of two large-bodied (Fig. 39) and broad-snouted species – P. gracilis and P. vincenti. Both Paludirex species were presumably semi-aquatic ambush predators likely capable of taking large-sized prey items, as can be inferred from the skull morphology which is largely consistent with that of extant semi-aquatic generalist crocodylians (such as a primarily dorsally opening external narial fenestra, a platyrostral snout, and large and conical teeth). The type species, P. vincenti, has a better understood morphology than P. gracilis thanks to its more complete holotype specimen. As a consequence, the diagnosis of the genus and differentiation between the two species must temporarily rely on the only shared elements between P. gracilis and P. vincenti, which are the premaxillae. The proportional differences between the premaxillae of P. gracilis and P. vincenti are appropriate to justify the specific distinction between them. Paludirex vincenti derives from Pliocene (and perhaps Pleistocene) deposits in southeast Queensland, whilst the P. gracilis material is from the Pleistocene of northwest Queensland. However, discovery of additional specimens referable to Paludirex may change the known spatiotemporal distribution of these two species. Species of Paludirex were one of the top predators from the Plio-Pleistocene of Australia, and their extinction is likely a consequence of environmental deterioration prompted by climatic changes that occurred in the late Pleistocene.

Jorgo Ristevski, Adam M. Yates, Gilbert J. Price, Ralph E. Molnar, Vera Weisbecker and Steven W. Salisbury. 2020. Australia’s Prehistoric ‘Swamp King’: Revision of the Plio-Pleistocene Crocodylian Genus Pallimnarchus de Vis, 1886. PeerJ. 8:e10466. DOI: 10.7717/peerj.10466

Crikey! Massive prehistoric croc emerges from South East Queensland