Friday, May 7, 2021

[Entomology • 2021] Oryctopterus varuna & O. yeshwanthi • Two New Species of the Genus Oryctopterus (Orthoptera: Stenopelmatidae: Oryctopinae) from India, with Some Notes on Biology

 

Oryctopterus varuna 
Hiremath & Prathapan, 2021



ABSTRACT
The genus Oryctopterus Karny, 1937 (Orthoptera, Stenopelmatidae, Oryctopinae) is reported from India for the first time and two new species, Ot. varuna sp. nov. and Ot. yeshwanthi sp. nov. are described. Male and female external genitalia of Ot. varuna sp. nov. and female genitalia of Ot. yeshwanthi sp. nov. are figured and described. Notes on seasonality, food habits and behavior of Ot. varuna sp. nov. are provided.

Keywords: Oriental Region, male genitalia, female genitalia, diet, behavior


Order Orthoptera Latreille, 1793
Family Stenopelmatidae Burmeister, 1838
Subfamily Oryctopinae Kevan, 1986

Genus Oryctopterus Karny, 1937

Oryctopterus varuna sp. nov.
 
49. Walking posture. 50. Defending a frontal attack.
51. Abdomen and fore-legs raised when poked on thorax. 52. Initiation of digging.
 Images not to scale.

Oryctopterus varuna sp. nov.

Etymology The new species is named after Varuna, the god of rains in Indian mythology. The name is a noun in apposition. This cricket was observed coming out to open areas such as campus roads following rains, hence the name. In the regional dialect, Ot. varuna sp. nov. is called ‘Mannunni’, meaning ‘child of soil’. Also nicknamed ‘Thanni-Pillai’, meaning ‘baby of water’, alluding to its emergence following rains.

Oryctopterus species.
48.Oryctopterus lagenipes (Karny, 1935), allotype, ♂, from Colombo, Sri Lanka (Karny 1937: pl. 7 fig. 2; available from Orthoptera species file).
49–52. Oryctopterus varuna sp. nov. 49. Walking posture. 50. Defending a frontal attack. 51. Abdomen and fore-legs raised when poked on thorax. 52. Initiation of digging.
Images not to scale.

Oryctopterus yeshwanthi sp. nov.

Etymology: This species is named after H.M. Yeshwanth, University of Agricultural Sciences, who collected the single known specimen.


S.R. Hiremath and K.D. Prathapan. 2021. Two New Species of the Genus Oryctopterus (Orthoptera: Stenopelmatidae: Oryctopinae) from India, with Some Notes on Biology. European Journal of Taxonomy. 748(1); 108–137. DOI: 10.5852/ejt.2021.748.1349

[Herpetology • 2021] Microhyla daklakensis & M. ninhthuanensis • Two New Cryptic Species of Microhyla Tschudi, 1838 (Anura, Microhylidae) related to the M. heymonsi Group from central Vietnam


(K, L) the holotype of Microhyla daklakensis sp. nov. (male); 
(M) the paratype of Microhyla ninhthuanensis sp. nov. (female);  
(I, J) Microhyla ‘heymonsi’ (male) 

Hoang, Nguyen, Ninh, Luong, ... et Jiang, 2021
Photographs by C.V. Hoang and N.L. Orlov.

Abstract
The Microhyla heymonsi species complex from central Vietnam was examined, and based upon morphological and molecular evidence, two new species are described. The discovery of Microhyla daklakensis sp. nov. and Microhyla ninhthuanensis sp. nov. brings the total number of known species in the genus to 46 and the species number of Microhyla in Vietnam to 13. The Truong Son Range harbors the highest diversity of the genus Microhyla with 11 recorded species so far. However, this apparent micro-endemic diversity is at risk because of habitat loss by deforestation, which highlights the necessity of further research leading to improved conservation measures.

Keywords: Microhyla, new species, central Vietnam, morphology, molecular phylogeny

Dorsolateral and ventral views of the specimens in life: Dorsolateral and ventral views of the specimens in life:
comparative specimen of M. ‘heymonsi’ (KPMĐ2018.42, male) (I, J);
 the holotype of Microhyla daklakensis sp. nov. (VNMN 06877, male) (K, L);
the paratype of Microhyla ninhthuanensis sp. nov. (ZISP 14254 (HAO186), female) (M).
Photographs by C.V. Hoang and N.L. Orlov.

Microhyla ninhthuanensis sp. nov.

Diagnosis: Microhyla ninhthuanensis sp. nov. is distinguished from its congeners by a combination of the following morphological characters: 1) body stocky, size medium (SVL 17.3–18.8 mm, n = 9 males; 21.6–23.6 mm, n = 2 females). 2) dorsum smooth; 3) head triangular, snout round in profile; 4) finger I shorter than one-half the length of finger II; 5) tips of all outer fingers dilated, forming disks, with a median longitudinal groove visible dorsally; 6) tips of all toes distinctly dilated into disks, with a weak median longitudinal groove visible dorsally, producing the appearance of two scutes; 7) inner metacarpal tubercle oval and prominent, paired outer metacarpal tubercle divided by a waist into two equal-sized parts: outer part quite round, inner part quite crescent; 8) tibiotarsal articulation of straightened limb not reaching snout; 9) webbing basal: I2 – 2½II2 – 3III3 – 4IV4⅓ – 3V; 10) inner metatarsal tubercles oval, prominent and outer metatarsal tubercles round; 11) upper eyelid without supraciliary spines; 12) narrow faint brown stripe extending from rear corner of eye to axilla; 13) light thin vertebral stripe present, canthus rostralis with dark lines; 14) small dark round spot at mid-dorsum, divided by a light vertebral stripe; 15) dorsum pinkish brown with dark brown marking in X-shape between eyes and arm, along vertebral and dorsolateral region stripes form wavy dust strip towards the groin, a small dark marking ‘ ()’-shaped in the center of the dorsum and mid-dorsal line; 16) an even black lateral stripe from above arm, almost reaching groin; 17) chin dark grey; throat white with scattered dark grey dusting; chest and belly creamy white.

Etymology: Specific epithet is in reference to the type locality, Ninh Thuan Province. We recommend “Ninh Thuan narrow-mouth frog” as the common English name and “Nhái bầu ninh thuận” as the Vietnamese name.

Natural history: All specimens were collected at night from 19:00 to 23:00 h on the ground near the banks of a small stream in the forest and on the sides of a recently constructed road next to the devastated forests (Fig. 6B). Larval stages and eggs of the new species are unknown.
 
Distribution: Microhyla ninhthuanensis sp. nov. is currently only known from the type locality in Phuoc Binh National Park, Ninh Thuan Province, Vietnam (Fig. 1). The species was recorded at an elevation of ca. 300 m a.s.l.


Microhyla daklakensis sp. nov.

Diagnosis: (1) Microhyla daklakensis sp. nov. is distinguished from its congeners by a combination of the following morphological characters: 1) body stocky, size medium (SVL 17.7–20.1 mm n = 4 males; 21.1–23.8 mm, n = 6 females), 2) dorsum smooth; 3) snout round in profile; 4) finger I longer than one-half the length of the finger II; 5) tips of all outer fingers dilated, forming disks, with a median longitudinal groove visible dorsally; 6) tips of all toes distinctly dilated into disks, with a weak median longitudinal groove visible dorsally, producing the appearance of two scutes; 7) inner metacarpal tubercle oval and prominent, paired outer metacarpal tubercle divided by a waistline into two equal-sized parts: outer part quite round, inner part crescent-shaped; 8) tibiotarsal articulation of straightened limb not reaching snout; 9) webbing basal: I2 – 2½II2 – 3III3 – 4IV4⅓ – 3V; 10) inner metatarsal tubercles oval, prominent and outer metatarsal tubercles round; 11) upper eyelid without supraciliary spines; 12) narrow faint brown stripe extending from rear corner of eye to axilla; 13) thin, pale vertebral stripe present, canthus rostralis with dark lines; 14) small dark round spot at mid-dorsum, divided by a light vertebral stripe; 15) dorsal surface yellowish brown, a dark brown marking in V-shape between eyes to insertion of arms; 16) vertebral and dorsolateral stripes form wavy dust strip towards the groin; 17) a small dark marking in ‘ ()’-shape on the center of the dorsum and mid-dorsal line; 18) an evenly colored black lateral stripe from above the insertion of the arms, almost reaching groin; 19) chin dark grey; throat white with scattered dark grey dusting; chest and belly creamy white.

Etymology: Specific epithet is in reference to the type locality, Dak Lak Province. We recommend “Dak Lak narrow-mouth frog” as the common English name and “Nhái bầu dak lak” as the Vietnamese name.

Natural history: All specimens were collected at night from 19:00 to 23:00 h on the ground near the banks of small temporary ponds formed after heavy rain, along the edges of the forest and on the sides of a recently constructed road next to the devastated forests (Fig. 6A). The new species was found in sympatry with four congeners including M. berdmorei, M. butleri, M. mukhlesuri, and M. pulchra, all of which were reproducing simultaneously with the new species in the same breeding site. Other anurans such as Fejervarya limnocharisOccidozyga cf. lima, and Occidozyga martensii also occurred in sympatry. Larval stages and eggs of the new species are unknown.

Distribution: Microhyla daklakensis sp. nov. is currently known only from the type locality in Nam Ka Nature Reserve, Krong No District, Dak Lak Province, Vietnam (Fig. 1). The species was recorded at an elevation of ca. 500 m a.s.l.

Figure 1. Map showing the type localities of Microhyla ninhthuanensis sp. nov. in Ninh Thuan Province (2) and Microhyla daklakensis sp. nov. in Dak Lak Province (1) in Tay Nguyen Plateau (Central Highlands) of Vietnam
 (E.J. Sterling and K Koy kindly provided the map).

Dorsolateral and ventral views of the specimens in life:
 comparative specimen of Microhyla neglecta (VNMN 07344, male) (A, B); (VNMN 07673, female) (C, D);
comparative specimen of M. pineticola (VNMN 07441, female) (E, F) and (VNMN 07455, male) (G, H).
Photographs by C.V. Hoang and N.L. Orlov.


 Chung Van Hoang, Tao Thien Nguyen, Hoa Thi Ninh, Anh Mai Luong, Cuong The Pham, Truong Quang Nguyen, Nikolai L. Orlov, Youhua Chen, Bin Wang, Thomas Ziegler and Jianping Jiang. 2021. Two New Cryptic Species of Microhyla Tschudi, 1838 (Amphibia, Anura, Microhylidae) related to the M. heymonsi Group from central Vietnam. ZooKeys. 1036: 47-74. DOI: 10.3897/zookeys.1036.56919


[Paleontology • 2021] Shuvuuia deserti • Evolution of Vision and Hearing Modalities in Theropod Dinosaurs


Shuvuuia deserti  Chiappe, Norell, & Clark, 1998

in Choiniere, Neenan, Schmitz, ... et Benson, 2021. 
 
Abstract
Owls and nightbirds are nocturnal hunters of active prey that combine visual and hearing adaptations to overcome limits on sensory performance in low light. Such sensory innovations are unknown in nonavialan theropod dinosaurs and are poorly characterized on the line that leads to birds. We investigate morphofunctional proxies of vision and hearing in living and extinct theropods and demonstrate deep evolutionary divergences of sensory modalities. Nocturnal predation evolved early in the nonavialan lineage Alvarezsauroidea, signaled by extreme low-light vision and increases in hearing sensitivity. The Late Cretaceous alvarezsauroid Shuvuuia deserti had even further specialized hearing acuity, rivaling that of today’s barn owl. This combination of sensory adaptations evolved independently in dinosaurs long before the modern bird radiation and provides a notable example of convergence between dinosaurs and mammals.




 Jonah N. Choiniere, James M. Neenan, Lars Schmitz, David P. Ford, Kimberley E. J. Chapelle, Amy M. Balanoff, Justin S. Sipla, Justin A. Georgi, Stig A. Walsh, Mark A. Norell, Xing Xu, James M. Clark and Roger B. J. Benson. 2021. Evolution of Vision and Hearing Modalities in Theropod Dinosaurs. Science. 372, 6542; 610-613. DOI: 10.1126/science.abe7941
 
 Michael Hanson, Eva A. Hoffman, Mark A. Norell and Bhart-Anjan S. Bhullar. 2021. The Early Origin of A Birdlike Inner Ear and the Evolution of Dinosaurian Movement and Vocalization. Science. 372, 6542. 601-609. DOI: 10.1126/science.abb4305

 
Revealing behavioral secrets in extinct species
Extinct species had complex behaviors, just like modern species, but fossils generally reveal little of these details. New approaches that allow for the study of structures that relate directly to behavior are greatly improving our understanding of the lifestyles of extinct animals (see the Perspective by Witmer). Hanson et al. looked at three-dimensional scans of archosauromorph inner ears and found clear patterns relating these bones to complex movement, including flight. Choiniere et al. looked at inner ears and scleral eye rings and found a clear emergence of patterns relating to nocturnality in early theropod evolution. Together, these papers reveal behavioral complexity and evolutionary patterns in these groups.

[Paleontology • 2021] The Early Origin of A Birdlike Inner Ear and the Evolution of Dinosaurian Movement and Vocalization



in Hanson, Hoffman, Norell et Bhullar, 2021.


Abstract
Reptiles, including birds, exhibit a range of behaviorally relevant adaptations that are reflected in changes to the structure of the inner ear. These adaptations include the capacity for flight and sensitivity to high-frequency sound. We used three-dimensional morphometric analyses of a large sample of extant and extinct reptiles to investigate inner ear correlates of locomotor ability and hearing acuity. Statistical analyses revealed three vestibular morphotypes, best explained by three locomotor categories—quadrupeds, bipeds and simple fliers (including bipedal nonavialan dinosaurs), and high-maneuverability fliers. Troodontids fall with Archaeopteryx among the extant low-maneuverability fliers. Analyses of cochlear shape revealed a single instance of elongation, on the stem of Archosauria. We suggest that this transformation coincided with the origin of both high-pitched juvenile location, alarm, and hatching-synchronization calls and adult responses to them.






 Michael Hanson, Eva A. Hoffman, Mark A. Norell and Bhart-Anjan S. Bhullar. 2021. The Early Origin of A Birdlike Inner Ear and the Evolution of Dinosaurian Movement and Vocalization. Science. 372, 6542. 601-609. DOI: 10.1126/science.abb4305
 
 Jonah N. Choiniere, James M. Neenan, Lars Schmitz, David P. Ford, Kimberley E. J. Chapelle, Amy M. Balanoff, Justin S. Sipla, Justin A. Georgi, Stig A. Walsh, Mark A. Norell, Xing Xu, James M. Clark and Roger B. J. Benson. 2021. Evolution of Vision and Hearing Modalities in Theropod Dinosaurs. Science. 372, 6542; 610-613. DOI: 10.1126/science.abe7941
 
Revealing behavioral secrets in extinct species
Extinct species had complex behaviors, just like modern species, but fossils generally reveal little of these details. New approaches that allow for the study of structures that relate directly to behavior are greatly improving our understanding of the lifestyles of extinct animals (see the Perspective by Witmer). Hanson et al. looked at three-dimensional scans of archosauromorph inner ears and found clear patterns relating these bones to complex movement, including flight. Choiniere et al. looked at inner ears and scleral eye rings and found a clear emergence of patterns relating to nocturnality in early theropod evolution. Together, these papers reveal behavioral complexity and evolutionary patterns in these groups.

[Paleontology • 2021] Cranial Anatomy of Besanosaurus leptorhynchus Dal Sasso & Pinna, 1996 (Reptilia: Ichthyosauria) from the Middle Triassic Besano Formation of Monte San Giorgio, Italy/Switzerland: Taxonomic and Palaeobiological Implications


Besanosaurus leptorhynchus Dal Sasso & Pinna, 1996

in Bindellini​, Wolniewicz, ... et Dal Sasso​, 2021. 

Abstract 
Besanosaurus leptorhynchus Dal Sasso & Pinna, 1996 was described on the basis of a single fossil excavated near Besano (Italy) nearly three decades ago. Here, we re-examine its cranial osteology and assign five additional specimens to B. leptorhynchus, four of which were so far undescribed. All of the referred specimens were collected from the Middle Triassic outcrops of the Monte San Giorgio area (Italy/Switzerland) and are housed in various museum collections in Europe. The revised diagnosis of the taxon includes the following combination of cranial characters: extreme longirostry; an elongate frontal not participating in the supratemporal fenestra; a prominent ‘triangular process’ of the quadrate; a caudoventral exposure of the postorbital on the skull roof; a prominent coronoid (preglenoid) process of the surangular; tiny conical teeth with coarsely-striated crown surfaces and deeply-grooved roots; mesial maxillary teeth set in sockets; distal maxillary teeth set in a short groove. All these characters are shared with the holotype of Mikadocephalus gracilirostris Maisch & Matzke, 1997, which we consider as a junior synonym of B. leptorhynchus. An updated phylogenetic analysis, which includes revised scores for B. leptorhynchus and several other shastasaurids, recovers B. leptorhynchus as a basal merriamosaurian, but it is unclear if Shastasauridae form a clade, or represent a paraphyletic group. The inferred body length of the examined specimens ranges from 1 m to about 8 m. The extreme longirostry suggests that B. leptorhynchus primarily fed on small and elusive prey, feeding lower in the food web than an apex predator: a novel ecological specialisation never reported before the Anisian in a large diapsid. This specialization might have triggered an increase of body size and helped to maintain low competition among the diverse ichthyosaur fauna of the Besano Formation.

Figure 3: The most complete skeletons of Besanosaurus leptorhynchus.  
 (A) PIMUZ T 1895; (B) BES SC 999; (C) PIMUZ T 4376 (with a Mixosaurus specimen above it); (D) PIMUZ T 4847.
Scale bars represent 50 cm.


Figure 4: Skull and mandible of Besanosaurus leptorhynchus holotype BES SC 999, and interpretative drawings.
 Grey dashed lines and grey labels indicate elements not visible on the surface, grey areas indicate background sediment, light grey areas indicate background bone.
 Scale bar represents 10 cm.

Figure 20: Cranial reconstruction of Besanosaurus leptorhynchus.
Articulated skull and mandible in (A) left rostrolateral, (B) caudal (occipital), (C) dorsal, (D) left lateral, and (E) ventral (palatal) view.
 Line drawings by Marco Auditore.

 Besanosaurus leptorhynchus Dal Sasso & Pinna, 1996



Conclusions: 
In general, the specimens here described preserve and represent a remarkably complete cranial anatomy, so that Besanosaurus leptorhynchus now is among the best-understood Middle Triassic Ichthyosaur taxa to date. Our revision of the skull morphology of this taxon clarified long-standing controversies regarding its cranial anatomy and the taxonomy of shastasaurids from Monte San Giorgio. Based on this rich fossil material, we have demonstrated that Mikadocephalus gracilirostris (GPIT 1793/1) is a junior synonym of Besanosaurus leptorhynchus, providing evidence to refute previous hypotheses (Maisch & Matzke, 1997a, 2000; Maisch, 2010) about the co-occurrence of two different shastasaurid taxa (Besanosaurus and Mikadocephalus) in the Besano Formation.

The six specimens here described represent a potential ontogenetic series covering a certain size range of mainly adult and potentially subadult specimens (Fig. 19), ordered by increasing size as follows: PIMUZ T 4376, PIMUZ T 1895, BES SC 999, BES SC 1016, GPIT 1793/1, PIMUZ T 4847. An allometric growth signal, yet to be fully tested, has also been detected. Other sources of intraspecific variation such as sexual dimorphism, cannot be ruled out, however, partly due to the limited dataset. Here we also report evidence that Besanosaurus was the largest Middle Triassic ichthyosaur taxon of the Western Tethys since we confidently estimate a fully adult size of about 8 m for specimen PIMUZ T 4847.

Besanosaurus possesses an extremely long, slender, and gracile snout, representing an ecological specialization never seen before the Anisian in a large sized (~8 m) diapsid. The diagnostic, prominent coronoid (preglenoid) process of the surangular and a large rugose area for the attachment of the mAMES allow to infer the presence of well-developed jaw closing muscles, which likely had an important functional role: we assume an efficient and fast jaw closing movement and hypothesize a snap-feeder-like hunting strategy, with a specific preference for small and elusive prey (such as coleoids and/or small fishes). Among the ichthyosaurian Besano-Monte San Giorgio Fauna (Cymbopondylus, mixosaurids, and Besanosaurus), different hunting strategies, demonstrated by different morphologies and dimensions of the rostra, should have led to the maintenance of low interspecific competition (i.e., niche partitioning). We also hypothesize that the specialization represented by a longirostrine morphology might have been driven by prey preference and the methods of prey capture. Mixosaurus and Cymbospondylus show almost a global distribution; on the contrary, Besanosaurus is known only from the Besano Formation (Italy and Switzerland). A wider distribution of this genus is expected (and supported by McGowan & Motani, 2003: 135–136): it seems unlikely to us that Besanosaurus would be represented only in the Alpine Tethys realm.

Last but not least, the importance of Besanosaurus is not only given by the completeness and remarkable preservation of its remains, and its ecological role, but also by the key phylogenetic position occupied by the taxon in the ichthyosaurian phylogeny: our analysis, performed with a matrix that includes around 90% of unambiguous scores for B. leptorhynchus and revised scores for other Triassic taxa, shows that this taxon represents the basalmost member of shastasaur-grade ichthyosaurs.


Gabriele Bindellini​, Andrzej S. Wolniewicz, Feiko Miedema, Torsten M. Scheyer and Cristiano Dal Sasso​. 2021. Cranial Anatomy of Besanosaurus leptorhynchus Dal Sasso & Pinna, 1996 (Reptilia: Ichthyosauria) from the Middle Triassic Besano Formation of Monte San Giorgio, Italy/Switzerland: Taxonomic and Palaeobiological Implications. PeerJ. 9:e11179. DOI: 10.7717/peerj.11179
 

[Botany • 2021] Re-evaluation of the Amazonian Hylaeaicum (Bromeliaceae: Bromelioideae) based on Neglected Morphological Traits and Molecular Evidence

 

Hylaeaicum eleutheropetalum

in Leme, Zizka, Paule, ... et Forzza, 2021.

Abstract
Generic status for the Amazonian Hylaeaicum is proposed within the Aechmea alliance, excluding it from the “Nidularioid complex” in general and from Neoregelia in particular. The monophyly of this new genus is supported by molecular phylogenetic analyses. The taxonomic circumscription of Hylaeaicum is based on the combination of geographical range and morphological characters, such as clonal growth, inflorescence structure, petal and corolla conformation, petal appendages, ovary, ovule, stigma, pollen, fruit, and seed, as well as seed anatomy, thoroughly documented and illustrated from field-collected specimens that flowered in cultivation in the Rio de Janeiro Botanical Garden, the Marie Selby Botanical Gardens, and in Refúgio dos Gravatás. The presence of seeds with long bicaudate appendages on both chalazal and micropylar ends is reported for the first time in Bromelioideae and considered an important character to distinguish Hylaeaicum from the related genera in the Aechmea alliance. In order to support the morphological distinctness of Hylaeaicum, the most varied and complete documentation of stigmata, fruits, and seeds of Bromelioideae is also presented for the first time, covering 24 genera and 17 subgenera. Fourteen new combinations, including 12 species and two varieties, are proposed.

Keywords: Aechmea alliance, morphology, “Nidularioid complex”, baccate fruits, appendaged seeds, Monocots



Elton M. C. Leme, Georg Zizka, Juraj Paule, Julián Aguirre-Santoro, Sascha Heller, Ivón M. Ramírez-Morillo, Heidemarie Halbritter, Jorge E. A. Mariath, Jordano D. T. de Carvalho and Rafaela C. Forzza. 2021. Re-evaluation of the Amazonian Hylaeaicum (Bromeliaceae: Bromelioideae) based on Neglected Morphological Traits and Molecular Evidence. Phytotaxa. 499(1); 1–60. DOI: 10.11646/phytotaxa.499.1.1

[Crustacea • 2021] Wiyufiloides osornoensis • A New Genus and Species of Groundwater Isopod of the Family Protojaniridae (Isopoda: Asellota: Gnathostenetroidoidea) from southern Chile


Wiyufiloides osornoensis
Pérez-Schultheiss & Wilson, 2021


Abstract
A new asellotan isopod of the family Protojaniridae Fresi, Idato & Scipione, 1980 is described from freshwater springs in the Osorno province, Los Lagos region, southern Chile. Wiyufiloides osornoensis gen. & sp. n. is the third South American protojanirid species and the first known groundwater isopod in Chile. The new genus and species is principally characterized by the presence of a vestigial antennal scale, a strongly subchelate pereiopod I and the absence of an apical lobe on the protopod of pleopod II. The new taxon is described in detail and figures are given.

Keywords: Isopoda, Protojaniridae, new genus, new species, Chile, groundwaters


Wiyufiloides osornoensis gen. & sp. n. 


Jorge Pérez-Schultheiss and George D. F. Wilson. 2021. A New Genus and Species of Groundwater Isopod of the Family Protojaniridae (Isopoda: Asellota: Gnathostenetroidoidea) from southern Chile. Zootaxa. 4966(5); 550–562. DOI: 10.11646/zootaxa.4966.5.4


[Paleontology • 2021] Sahonachelys mailakavava • A New Pelomedusoid Turtle (Pleurodira: Sahonachelyidae) from the Late Cretaceous of Madagascar provides Evidence for Convergent Evolution of Specialized Suction Feeding among Pleurodires


 Sahonachelys mailakavava
Joyce, Rollot, Evers, Lyson, Rahantarisoa & Krause, 2021

 Artwork by Andrey Atuchin.

Abstract
The Maevarano Formation in northwestern Madagascar has yielded a series of exceptional fossils over the course of the last three decades that provide important insights into the evolution of insular ecosystems during the latest Cretaceous (Maastrichtian). We here describe a new genus and species of pelomedusoid turtle from this formation, Sahonachelys mailakavava, based on a nearly complete skeleton. A phylogenetic analysis suggests close affinities of Sahonachelys mailakavava with the coeval Madagascan Sokatra antitra. These two taxa are the only known representatives of the newly recognized clade Sahonachelyidae, which is sister to the speciose clade formed by Bothremydidae and Podocnemidoidae. A close relationship with coeval Indian turtles of the clade Kurmademydini is notably absent. A functional assessment suggests that Sahonachelys mailakavava was a specialized suction feeder that preyed upon small-bodied invertebrates and vertebrates. This is a unique feeding strategy among crown pelomedusoids that is convergent upon that documented in numerous other clades of turtles and that highlights the distinct evolutionary pathways taken by Madagascan vertebrates.

Keywords: Maastrichtian, Maevarano Formation, Sahonachelyidae, Pleurodira, Late Cretaceous, Testudines 

Figure 1. (a) Outcrop map of Late Cretaceous and Palaeocene strata in the Mahajanga Basin of northwestern Madagascar (see inset at lower right). The location of the Berivotra Study Area is highlighted by the rectangle. The holotype specimen of  Sahonachelys mailakavava gen. et sp. nov. (UA 10581) was recovered from locality MAD05-38 in the Anembalemba Member of the Maevarano Formation (see stratigraphic relations in inset at upper left), which is of latest Cretaceous (Maastrichtian) age.
(b) Locality MAD05-38, type locality of  Sahonachelys mailakavava, view looking north-northwest.
(c) Close-up view of quarry face at locality MAD05-38 showing longitudinal cross-section of UA 10581 above (white arrow, caudal end of specimen to the right) and large fragments of specimen in foreground (black arrows).

     

Systematic palaeontology

Testudines Batsch, 1788 
Pleurodira Cope, 1865 
Pelomedusoides Broin, 1988 

Sahonachelyidae new clade name

Registration number. The clade name Sahonachelyidae is registered at RegNum with the number 570.

Definition. The largest extinct clade containing Sahonachelys mailakavava gen. et sp. nov.

Composition. Sahonachelyidae is currently hypothesized to consist of Sahonachelys mailakavava and Sokatra antitra, two extinct turtles from the Maastrichtian of Madagascar.


Figure 3. Sahonachelys mailakavava gen. et sp. nov., UA 10581, holotype, Late Cretaceous (Maastrichtian), Mahajanga Basin, Maevarano Formation, Madagascar. Photograph of skull with hyoid in (a) dorsal, (b) ventral and (c) left lateral views.

Figure 5. Sahonachelys mailakavava gen. et sp. nov., UA 10581, holotype, Late Cretaceous (Maastrichtian), Mahajanga Basin, Maevarano Formation, Madagascar. Three-dimensionally rendered model and line drawing of skull in (a) right lateral, (b) left lateral, (c) posterior and (d) anterior views.

ap, antrum postoticum; bs, basisphenoid; ex, exoccipital; fnh, foramen nervi hypoglossi; fpo, foramen postoticum; fr, frontal; ica, incisura columella auris; ju, jugal; mx, maxilla; op, opisthotic; pa, parietal; pal, palatine; pcf, precolumellar fossa; pf, prefrontal; pm, premaxilla; po, postorbital; pop, posterior opening of antrum postoticum; pp, posterior process of the maxilla; pt, pterygoid; qj, quadratojugal; qu, quadrate; so, supraoccipital; sq, squamosal.


Figure 9. Sahonachelys mailakavava gen. et sp. nov., UA 10581, holotype, Late Cretaceous (Maastrichtian), Mahajanga Basin, Maevarano Formation, Madagascar. Photograph and line drawing of shell in (a) dorsal and (b) ventral views. The lone Roman numerals indicate the neurals.
 Ab, abdominal scute; An, Anal scute; co, costal; Eg, extragular scute; ent, entoplastron; epi, epiplastron; Fe, femoral scute; Gu, gular scute; Hu, humeral scute; hyo, hyoplastron; hyp, hypoplastron; mdf, musk duct foramen; Ma, marginal scute; mes, mesoplastron; nu, nuchal; Pe, pectoral scute; per, peripheral; Pl, pleural; py, pygal; sp, suprapygal; Ve, vertebral scute; xi, xiphiplastron.


Sahonachelys mailakavava gen. et sp. nov.

Type locality. Locality MAD05-38, Berivotra Study Area, approximately 35 km southeast of the city of Mahajanga, Boeny Region, Madagascar. GPS coordinates are archived at the Denver Museum of Nature & Science and the University of Antananarivo and are available to qualified researchers.

Type stratum. Anembalemba Member, Maevarano Formation, dated to the Late Cretaceous (Maastrichtian, see §2 Geological setting).
 
Etymology. The name Sahonachelys mailakavava combines the Malagasy words ‘sahona' (pronounced sah-WHO-nah) for frog, ‘mailaka' (pronounced my-LAH-kah) for quick, ‘vava' (pronounced VAH-vah) for mouth, and the Greek word ‘chelys' for turtle to mean ‘quick-mouthed frog turtle’ in allusion to the frog-like appearance of the skull and its inferred quick mode of suction feeding.

Diagnosis. Sahonachelys mailakavava gen. et sp. nov. can be diagnosed as a member of Pan-Pelomedusoides by presence of midline contact of prefrontals; presence of processus trochlearis pterygoidei; contact of postorbital with palatine resulting in formation of expanded septum orbito-temporale; involvement of prootic and/or quadrate in formation of foramen posterius canalis carotici interni; the absence of nasals, vomer and splenial; low-domed, oval shell; sutural contact of pelvis with shell; the absence of cervical scutes; reduction in neural count resulting in midline contact of posterior costals; broad plastron; equidimensional mesoplastra; single, median gular; and cervical column consisting of procoelous vertebrae. The shell of S. mailakavava can be distinguished from those of all other pan-pelomedusoids by the presence of elongate gular that broadly crosses entoplastron and fully hinders midline contact of extragulars and humerals (also present in the kurmademydine Jainemys pisdurensis and the taphrosphyines Taphrosphys sulcatus and Ummulisani rutgersensis) in addition to broad contribution of enlarged extragulars to margin of anterior plastral lobe resulting in reduced contribution from gular. The cranium of S. mailakavava can be distinguished from those of all members of the clade formed by Podocnemidoidae and Bothremydidae by plesiomorphic retention of deep temporal emarginations that results in reduced or absent squamosal-quadratojugal and parietal-quadratojugal contacts, retention of clear exposure of prootic in ventral view, laterally open foramen jugulare posterius, and the absence of cavum pterygoidei or fossa pterygoidea. The cranium of S. mailakavava can be distinguished from those of all remaining, more basal-branching representatives of Pan-Pelomedusoides (i.e. Araripemydidae, Pelomedusidae and Atolchelys lepida), but resembles those of Sokatra antitra, Bothremydidae and Podocnemidoidae in derived presence of posterior enclosure of incisura columella auris by quadrate to exclusion of Eustachian tube; flooring of processus paroccipitalis by expanded sheet of bone formed by basisphenoid, quadrate and basioccipital; quadrate-exoccipital contact; reduced ventral exposure of prootic (the latter two characters also present in Araripemydidae); short basioccipital; and exclusion of basioccipital from occipital condyle (absent in Podocnemidoidae). Among pan-pelomedusoids, S. mailakavava uniquely resembles Sokatra antitra by the presence of an elongate posterior process of the maxilla; formation of deeply interfingered sutural contact between jugal and maxilla; reduced ventral process of quadratojugal; formation of foramen posterius canalis carotici interni by basisphenoid, quadrate and prootic; and strong forward inclination of processus articularis. These characteristics serve to diagnose the clade Sahonachelyidae. Sahonachelys mailakavava differs from Sokatra antitra by having a much flatter and broader cranium with more dorsally oriented orbits, presence of prefrontal-palatine contact, absence of parietal-palatine contact, presence of narrower triturating surfaces that lack lingual ridge, shorter midline contact between palatines, presence of distinct supramaxillary artery sulcus on ventral side of jugal, and exposure of prootic anterior and posterior to foramen posterius canalis carotici interni.

Figure 11. A reconstruction of Sahonachelys mailakavava gen. et sp. nov. preying upon young larvae of the giant Madagascan frog Beelzebufo ampinga using specialized suction feeding.
 Artwork by Andrey Atuchin.

Conclusion: 
We here describe a new species of pelomedusoid turtle, Sahonachelys mailakavava, based on a near-complete skeleton from the Maevarano Formation of northwestern Madagascar, which has been dated Late Cretaceous (Maastrichtian). The new species can easily be diagnosed relative to all other named pleurodires as it shows a large number of unique characters in both the shell and cranium. A phylogenetic analysis using weighted parsimony indicates that Sahonachelys mailakavava is sister to Sokatra antitra and that these coeval Madagascan turtles are the only known representatives of the newly recognized clade Sahonachelyidae. This clade is sister to the group formed by Bothremydidae and Podocnemidoidae within crown Pelomedusoides. The most conspicuous characteristic of this clade is the presence of an extended posterior process that is formed by the maxilla and protrudes deeply into the lower temporal emargination. A number of highly unusual morphological features suggest that Sahonachelys mailakavava was a specialized, aquatic, suction-feeding species that fed upon moving prey. The specialized feeding strategy further highlights the uniqueness of Late Cretaceous Madagascan faunas, as no other crown pelomedusoid is known to have developed this method of prey capture.

   
 
 
Walter G. Joyce, Yann Rollot, Serjoscha W. Evers, Tyler R. Lyson, Lydia J. Rahantarisoa and David W. Krause. 2021. A New Pelomedusoid Turtle, Sahonachelys mailakavava, from the Late Cretaceous of Madagascar provides Evidence for Convergent Evolution of Specialized Suction Feeding among Pleurodires. Royal Society Open Science. DOI: 10.1098/rsos.210098

     

Thursday, May 6, 2021

[Herpetology • 2021] Systematic Status of the Rare Himalayan Wolf Snake Lycodon mackinnoni Wall, 1906 (Serpentes: Colubridae)


Lycodon mackinnoni Wall, 1906 

Photo by Abhijit Das

Abstract
Lycodon mackinnoni is a poorly known Himalayan endemic snake known from Western Himalaya. Since the original description of L. mackinnoni almost 112 years ago, this species was not reported from its type locality and its phylogenetic position remain unknown. We herein, provide detail morphological description, comparison with type material, phylogenetic relationship with its congeners and new natural history information.

Keywords: Reptilia, Colubrids, DNA, Himalayas, Lycodon, rediscovery, taxonomy

Lycodon mackinnoni (WII- ADR197). ex-situ.  
Photo by Abhijit Das




Swati Nawani, V. Deepak, Kumudani Bala Gautam, Sandeep Kumar Gupta, Bitupan Boruah and Abhijit Das. 2021. Systematic Status of the Rare Himalayan Wolf Snake Lycodon mackinnoni Wall, 1906 (Serpentes: Colubridae). Zootaxa. 4966(3); 305–320. DOI: 10.11646/zootaxa.4966.3.3