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Research Article
A new species of Phalotris (Serpentes, Colubridae, Elapomorphini) from Paraguay
expand article infoPaul Smith‡§, Jean-Paul Brouard§, Pier Cacciali§|
‡ FAUNA Paraguay, Encarnación, Paraguay
§ Para La Tierra, Centro IDEAL, Pilar, Paraguay
| Guyra Paraguay, Asunción, Paraguay
¶ Instituto de Investigación Biológica del Paraguay, Asunción, Paraguay

Corresponding author: Paul Smith ( faunaparaguay@gmail.com )

Academic editor: Johannes Penner
© 2022 Paul Smith, Jean-Paul Brouard, Pier Cacciali.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Smith P, Brouard J-P, Cacciali P (2022) A new species of Phalotris (Serpentes, Colubridae, Elapomorphini) from Paraguay. Zoosystematics and Evolution 98(1): 77-85. https://doi.org/10.3897/zse.98.61064
ZooBank: urn:lsid:zoobank.org:pub:34A3908E-9431-4B2F-A967-773F5D9AEF0C
Open Access

Abstract

A new species of Phalotris from the nasutus group, Phalotris shawnella sp. nov., is described. It can be distinguished from the other members of the group by having the following combination of characters: 1) fifth supralabial in contact with parietal, 2) vertebral stripe present, 3) yellowish nuchal collar (2 or 3 dorsal scales long), 4) dull reddish color of head, 5) broad, solidly or near solidly dark, lateral bands, 6) red-orange ventral scales lightly and irregularly spotted with black mainly on the posterior half of the body and 7) a bilobed, extremely asymmetrical hemipenis, with enlarged, curved, lateral spines. The species is only known from a recent specimen collected in the Cerrado zone of northeastern Paraguay at Rancho Laguna Blanca, San Pedro department, and two photographic records of live specimens from this and an additional locality. Limited ecological data based on observations of a captive individual, and a wild record, are provided, and a conservation assessment is performed for this extremely limited range Paraguayan endemic snake.

Resumen

Se presenta la descripción de una nueva especie de Phalotris del grupo nasutus, Phalotris shawnella sp. nov. puede ser diferenciada de otros miembros del grupo por tener la siguiente combinación de caracteres: 1) quinta supralabial en contacto con la parietal, 2) presencia de una estría vertebral oscura, 3) collar nucal amarillento (de 2 ó 3 escamas de ancho), 4) coloración rojiza en la cabeza, 5) ancha faja lateral muy oscura o bastante oscura, 6) escamas ventrales rojo-anaranjadas e irregularmente salpicadas de negro principalmente en la parte posterior del cuerpo, y 7) hemipenes bilobados, extremadamente asimétricos, con espinas laterales agrandadas y curvas. La especie se la conoce únicamente de un ejemplar colectado en el Cerrado en el noreste de Paraguay en el Rancho Laguna Blanca, departamento de San Pedro, además de dos registros fotográficos de ejemplares vivos, uno de esta misma localidad y otro de una localidad adicional. Se proveen datos ecológicos limitados, en base a observaciones de un ejemplar en cautiverio, y otro en la naturaleza, así como una propuesta de evaluación del estado de conservación para este endemismo de Paraguay de rango extremadamente limitado.

Key Words

endemic, hemipenis, Phalotris nasutus, Phalotris shawnella sp. nov.

Palabras claves

endémico, hemipene, Phalotris nasutus, Phalotris shawnella sp. nov.

Introduction

The genus Phalotris Cope, 1862 is a group of small to medium-sized, semi-fossorial snakes, distributed largely in open areas of Brazil, Bolivia, Paraguay, Uruguay, and Argentina (Ferrarezzi 1993). Though Cope (1862) described the genus, it was treated as a synonym of Elapomorphus Wiegmann, 1843 by most authors for over a century, until its revalidation by Ferrarezzi (1993) who considered it a monophyletic group close to Apostolepis Cope, 1862. More recently, Grazziotin et al. (2012) using five mitochondrial and three nuclear gene sequences showed Phalotris as the most primitive genus within the Elapomorphini, although this conclusion was only weakly supported.

The genus is poorly represented in museum collections, but 14 species are currently recognized separated into three species groups (Ferrarezzi 1993): the tricolor group of five species (Jansen and Köhler 2008), the bilineatus group with four species (Puorto and Ferrarezzi 1993; Cacciali and Cabral 2015) and the nasutus group which includes five species (Moura et al. 2013). Following Entiauspe-Neto et al. (2021) we do not recognize the recently-described P. cerradensis Silveira, 2020 of this latter group as a valid species.

Two synapomorphies distinguish the nasutus group: a pointed snout with prominent rostral shield; and fusion between the second and third series of temporal plates (sometimes on only one side of the head) (Ferrarezzi 1993; Moura et al. 2013). The five known species all occur in the Cerrado region of central South America: Phalotris concolor Ferrarezzi, 1993, Phalotris labiomaculatus Lema, 2002, Phalotris lativittatus Ferrarezzi, 1993, Phalotris nasutus (Gomes, 1915), and Phalotris nigrilatus Ferrarezzi, 1993.

The only species of the nasutus group currently recorded from Paraguay is the endangered endemic P. nigrilatus. This species was described from a single female specimen (FML 709) collected at “Carumbé”, in the Paraguayan department of San Pedro, in 1973. The redescription of this species, including a description of the hemipenes, by Cacciali et al. (2007), was based on two further specimens (MNHN[M] 89 and 91) from “Primavera”, also San Pedro department (as the holotype), that were collected in 1957. Subsequently, additional specimens of P. nigrilatus that had been collected at the latter locality between 1954 and 1959 (NHM 1955.1.5.99, 1955.1.6.2–3, 1956.1.3.48–51, 1956.1.16.39–40, 1958.1.2.31, 1960.1.3.5–8, 1962.110) were also located (Cacciali et al. 2016). Cacciali et al. (2020) summarized the morphological data of these specimens, providing images of the first live specimen and discussing variation in pholidosis of the species.

During field work at Rancho Laguna Blanca (San Pedro department, northeastern Paraguay) (Fig. 1) two specimens of a Phalotris nasutus group snake were captured, that exhibited intermediate characters between P. nigrilatus and P. lativittatus (the latter not previously recorded in Paraguay). With the photographing of an additional specimen at a second locality (Colonia Volendam, San Pedro department) we undertook an extensive revision of specimens and the literature, and it became apparent that the differences were consistent and clear enough to indicate species level differentiation. Here we describe this as a new species of Phalotris of the nasutus group.

Figure 1. 

Known localities for Phalotris shawnella sp. nov. in San Pedro department, Paraguay Square: type locality. Circle: additional locality at Colonia Volendam.

Materials and methods

Measurements of cephalic scales were taken on the left side of the body with dial callipers (accurate to 0.1 mm) and body lengths were measured with millimeter tape. Body lengths include snout-vent length (SVL) and tail length (TL). Descriptions of coloration are provided for live and fixed specimens. Ventral scale counts follow Dowling (1951). Dorsal scale counts and terminology follow Peters (1964), recording reduction. For supralabial counts, numbers in parentheses are those scales that contact the orbit and, likewise for infralabial counts, the numbers in parentheses are the scales in contact with the chin shields. First and second rows of temporals were counted. Paired structures are presented in right/left orientation. The right hemipenis of the specimen was everted directly after euthanizing, and hemipenial terminology follows Zaher (1999). We follow Ferrarezzi (1993) for the designation of the groups. Behavioral data were collected from observations on a specimen kept briefly in captivity.

Geographic and morphological data used for comparisons with other species within the nasutus group were extracted from Ferrarezzi (1993) for P. nasutus, Ferrarezzi (1993) and Silveira Vasconcelos and Gomes dos Santos (2009) for P. lativittatus, Moura et al. (2013) for P. concolor, and Hamdan et al. (2013) for P. labiomaculatus. A list of examined specimens of P. nigrilatus and P. multipunctatus is provided in Appendix 1. Museum codes in the appendix are as follows: NHM Natural History Museum, London, UK; CZPLT Colección Zoológica Para La Tierra, Pilar, Paraguay. Given that information on P. labiomaculatus is not provided for specific specimens, we used pholidosis traits of this species for comparison of ranges but not for correlations. Morphological data were used to explore the variation in ventral and subcaudal scales among the species in the group.

Geographic baseline data (high resolution elevation maps) were taken from Consortium for Spatial Information (CGIAR-CSI), based on SRTM30 images (30 seconds resolution), available at www.diva-gis.org/gdata (Jarvis et al. 2008). Ecoregion definition was based on Olson et al. (2001). GIS processing was performed in Quantum GIS 3.12.0.

Results

Phalotris shawnella sp. nov.

http://zoobank.org/253E6610-D61C-49B7-B79F-0625C8FB72A5

Type locality

Rancho Laguna Blanca, Departamento San Pedro, Paraguay (Fig. 1).

Holotype

CZPLT-H-594; adult male; collected during digging on 3 January 2014 (J-P. Brouard); Rancho Laguna Blanca, 23°48'43"S, 56°17'49"W (WGS 84), 204 masl, San Pedro department. Specimen complete but damaged during collection, being severed approximately at mid-body (Fig. 2).

Figure 2. 

Dorsal (left) and ventral (right) overviews of the holotype of P. shawnella sp. nov. The specimen was accidentally severed during collection. Scale bar: 2 cm. (Photograph by Jeremy Dickens).

Diagnosis

Phalotris shawnella sp. nov. is assigned to the nasutus group on account of the pointed snout with prominent rostral shield and the fusion of the second and third temporal plates (Fig. 3A). The new species can be distinguished from all other members of the nasutus group by the combination of the following characters: 1) fifth supralabial in contact with parietal, 2) vertebral stripe present, 3) yellowish nuchal collar (2 or 3 dorsal scales long), 4) dull reddish color of head in adults, 5) broad, solidly or near solidly dark lateral bands, 6) red-orange ventral scales lightly and irregularly spotted with black, mainly on the posterior half of the body, and 7) a bilobed, extremely asymmetrical hemipenis, with enlarged, curved, lateral spines.

Figure 3. 

Coloration in life of P. shawnella sp. nov. A. Detail of the head of the holotype (CZPLT-H-594); B. Dorsolateral view of the holotype; C. Juvenile topotype specimen, kept in captivity and which later escaped; D. Live specimen photographed at Colonia Volendam. (A–C photographed by Jean-Paul Brouard, D photographed by Marko Fast).

Phalotris shawnella sp. nov. is differentiated from the individual members of the nasutus group and the only species known to occur sympatrically with it (P. multipunctatus) as follows. (The characteristics of Phalotris shawnella sp. nov. are given first, followed by the comparison species in parentheses):

Phalotris nasutus Gomes, 1915: 1) broad black lateral bands running the length of the body (absent in P. nasutus or present vestigially on the posterior part of the body only); 2) supralabial concolorous with head (supralabials paler than head); 3) ventral coloration red-orange with blackish smudges on the lateral part of the ventral scales, and scattered larger irregular black blotches (ventral immaculate pink); 4) ventral scales 185 in the male (ventrals in males < 182); 5) hemipenis bilobed and greatly asymmetrical (hemipenis only slightly asymmetrical).

Phalotris lativittatus Ferrarezzi, 1993. Superficially closest to this species within the nasutus group, which shows little variation in appearance across the large range and specimen series available (H. Braz in litt.). It can be reliably distinguished from P. shawnella sp. nov. with the following characters: 1) Supralabials uniformly brownish red (supralabials pale in P. lativittatus); 2) infralabials uniformly grey (infralabials with some dark markings); 3) scattered dark spots along the sides of the ventral scales (uniform pale ventral scales); 4) broad lateral band solid or nearly solid (lateral band with broad pale scale edges along entire length); 5) small spines at the lower part of the hemipenis (larger spines all along the body of the hemipenis).

Phalotris nigrilatus Ferrarezzi, 1993. Geographically, this is the only species that approaches P. shawnella sp. nov. within the nasutus group and is the only species with which it shares two key characters: a solid dark lateral band and dark markings on the ventral scales. Phalotris nigrilatus is otherwise phenotypically strikingly different and the significant specimen series now available indicates that it is morphologically very conservative (Cacciali et al. 2020). 1) Presence of clear pale collar (absence of collar in P. nigrilatus); 2) Ventral dark markings irregular, diffuse and widely-spaced, mainly on the posterior half of the body (ventral dark markings dense and typically regular, at the edges of each ventral scale and along the entire underside); 3) Chinshields pale contrasting with dark infralabials (chinshields dark, not contrasting with infralabials); 4) Head brick red dorsally with brownish suffusions in adult (head black in adult); 5) thin spines on the hemipenis (thick spines).

Phalotris concolor Ferrarezzi, 1993: 1) fifth supralabial in contact with parietal (separated in P. concolor); 2) presence of broad dark lateral band (lateral coloration uniformly red); 3) indistinct black vertebral line (dorsal coloration uniformly red); 4) ventral scales 185 in the male (212 ventral scales in the only male known).

Phalotris labiomaculatus Lema, 2002. 1) Supralabials uniformly brownish-red, concolorous with rest of head (spotted black and white supralabials in P. labiomaculatus); 2) wide dark lateral band (body coloration uniformly orange with no dark lateral band); 3) yellow nuchal collar 2–3 scales wide (white nuchal collar 3–4 scales wide); 4) dark vertebral line present (no vertebral line); 5) irregular dark spots on the ventral scales (uniformly white ventral scales).

Phalotris multipunctatus Puorto & Ferrarezzi, 1993. This is the only species of Phalotris known to occur sympatrically with P. shawnella. 1) Scales of broad lateral bands lacking white spotted pattern (scales of broad lateral bands with white tips giving spotted pattern in P. multipunctatus); 2) red-orange ventral scales lightly and irregularly spotted with black, mainly on the posterior half of the body (ventral scales black with broad white posterior edges forming banded pattern); 3) head brick red (in adult) or black (in juvenile) lacking any white spotting (head black with profuse white spotting); 4) infralabials uniform (each infralabial with a single large white medial spot); 5) longitudinal dark mid-dorsal stripe present (longitudinal dark mid-dorsal stripe absent).

Description of holotype

An adult male in two pieces, SVL 260 + 140 (=400) mm; TL 65 mm (16.25% of SVL); one preocular, two postoculars; temporals 0+1/0+1; loreal absent; supralabials 6(2–3)/6(2–3), fifth supralabial broadly contacts parietal; infralabials 7(1–5)/7(1–5), 1st to 4th contacting the anterior pair of chinshields and 4th to 5th contacting the posterior pair of chinshields; posterior chinshields longer and thinner than anterior chinshields; dorsal scale rows 15-15-15; scales smooth lacking apical pits; 185 ventrals; anal plate divided; 35 paired subcaudals. Yellow nuchal collar two to three scales wide and posterior black collar one to two scales wide. Slight trace of incomplete anterior black collar, most evident laterally. Rostral prominent and wider than it is long (1.9 × 2.6 mm); nasal complete, twice as long as greatest width (2.2 × 1.1 mm), contacting the rostral anteriorly, the 1st and 2nd supralabial ventrally, the preocular posteriorly, and the internasal and frontal dorsally; paired internasals slightly wider than they are long (1.4 × 2.2 mm); the second temporal longer than wide (3.1 × 1.4 mm); preocular longer than wide (1.3 × 0.9 mm), contacting 2nd supralabial; two postoculars as long as wide (approximately 0.6 × 0.6 mm), the lower postocular contacting the 3rd to 5th supralabials and only slightly smaller than the upper; single prefrontal twice as wide as long (2.3 × 4.2 mm); supraocular twice as long as wide (2.2 × 1.2 mm); frontals slightly longer than they are wide (3.6 × 2.8 mm); paired parietals twice as long as wide (6.0 × 3.1 mm). No differences in shape in right/left sides. Eye diameter 1.1 mm.

Hemipenis morphology

Semicalyculate and semicapitate (Fig. 4). Long, slender and bilobed, distinctly asymmetrical (right lobe -from asulcate view- 2/3 shorter), with enlarged, curved, lateral spines (13 to 15 large spines on each side). Sulcus furcation located in basal third and branches centrolinear. Note that right lobe (from asulcate view) is not fully everted, missing ca. 1 mm.

Figure 4. 

Hemipenis of P. shawnella showing the asulcate (left) and sulcate (right) views. Gray bar = 3 mm. (Photograph by Paul Smith).

Color in life

Head brick red dorsally, with slightly darker suffusions, and uniformly brownish red on supralabials; red-orange ventrally with a greyish tinge to the first three infralabials, and whitish chin shields. A single row of scales on the posterior part of the dorsal surface of the head shows traces of a faint black anterior collar, mainly laterally. A broad yellow collar fades laterally and is followed by a thinner black collar (Fig. 3B). Neither collar is visible ventrally. Body coloration brick red dorsally, with a faint trace of a thin black vertebral line formed by a small dark spot anteriorly on each vertebral scale connected by a thinner black streak along the center of the scale that is variably conspicuous along the length of the body and fades out upon reaching the tail. Broad black (to brownish-black) lateral lines running the length of the body from the posterior black collar to the tip of the tail. Lateral bands uniformly 3–3.5 scales wide over the entire length of the body, narrowing only slightly to 2 scales width on the tail. Ventrally red-orange, the edges of some of the ventral scales with small black, diffuse blotches (more prominent on the posterior ventral scales). Medial parts of the ventral scales are largely uniform apart from a very small number of often large black smudges, irregularly dispersed on the midbody region.

Color in preservative

Head fades to dull brownish (Fig. 2). Yellow collar to pinkish white. Black lateral and vertebral lines dark blackish-brown. Brick red of dorsum fades to brownish. Ventrally, the coloration is creamy-white, slightly yellower medially on the ventral scales and towards the tail, whiter laterally on the ventral scales and towards the head.

Variation

Described on the basis of an individual captured (on 9 December 2013) close to the collection locality of the holotype, which was photographed (Fig. 3C) and which later escaped. This individual was smaller and presumed to be juvenile female (weight 7 g), SVL 250 mm, TL 20 mm. It initially showed extensive black coloration on the head, broadly suffused with brick red dorsally, but the red areas became more prominent over its few months in captivity – a possible ontogenic change. The yellow nuchal collar was broader (3 to 4 scales wide) and paler, being creamy yellow as opposed to orange-yellow. The posterior black nuchal collar was absent dorsally, with the black mid-dorsal line forming a broad, smudgy spot covering an entire scale where it contacted the yellow nuchal collar, and bordered either side by a single orange scale between it and the black lateral bands. Dorsally, it was a deeper red, and ventrally it was a deeper orange-red, than the holotype. Dorsals 15-15-15, ventrals 197, subcaudals 26 (divided), temporals 0+1/0+1. Additional images of the known specimens are stored in FigShare (https://doi.org/10.6084/m9.figshare.c.5804246.v1).

Etymology

The species name is a combination of the first names of two remarkable young people who were born around the same time as Fundación Para La Tierra, and who inspired its founders to work towards the study and conservation of the Paraguayan fauna, so that one day they might inherit a better world: Shawn Ariel Smith Fernández and Ella Bethany Atkinson. The epithet is not Latin, is invariable (word in apposition) and is made up of elements of both of their names.

Ecology

The holotype was collected by day in Cerradón forest on a sandy substrate, close to disturbed bushy Cerrado and within 500 m of a lake shore (Fig. 5). The topotype (juvenile female) was kept in captivity for ecological observations, but unfortunately later escaped. Nine days after capture (on 18 December 2013) it was offered a Gymnophthalmid lizard (Vanzosaura rubricauda) with 0.7 g mass and 55 mm total length, which it had consumed by the following day. On 22 December 2013 it was offered another V. rubricauda, of similar size, and by the next day the tail of the lizard was missing; it later consumed the rest of the lizard on 25 December 2013. Two days later, the snake drank water.

Figure 5. 

Collection locality of holotype, Rancho Laguna Blanca, San Pedro department, Paraguay. (Photograph by Para La Tierra).

A third individual showing the clear diagnostic characters of this species (Fig. 3D) was photographed in leaf litter 500 m outside of the settlement of Colonia Volendam (24°16'28.6"S, 57°01'25.3"W), San Pedro department (Fig. 1) by Marko Fast on 10 March 2019, at 13:36 h, in a small patch (0.29 km2) of degraded Cerradón forest. When encountered, the individual had both the head and tail hidden under the leaf litter. The specimen did not show any aggressive behavior, and was released after being photographed.

Discussion

Phalotris shawnella sp. nov. is a distinctive new species of Phalotris and is only the second member of the genus to show dark mottling on the ventral side – a character previously considered to be an autapomorphy of P. nigrilatus (Cacciali et al. 2007). In fact, with the discovery that the rostral and prefrontal scale contact is a variable character (Cacciali et al. 2020), the only remaining autapomorphies of P. nigrilatus are the black head and the lack of a nuchal collar. Phalotris shawnella sp. nov. has less dark and less regular black pigmentation on the belly than P. nigrilatus, suggesting that it is perhaps a transitional form between this last species and the other members of the nasutus group. Indeed, P. shawnella sp. nov. is, in many ways, morphologically intermediate between P. nigrilatus and P. lativittatus. All three species (P. lativittatus, P. shawnella sp. nov., and P. nigrilatus) also have a low number of ventral scales when compared to other Phalotris, with only P. nasutus having less. Both P. lativittatus and P. nigrilatus are known from respectable specimen series that show they are both morphologically conservative and show minimal variation (H. Braz pers. com.; Cacciali et al. 2020), whilst the three known examples of P. shawnella sp. nov. also share the same consistent diagnostic characteristics at both localities at which they have been recorded.

The nasutus group has not been the subject of any recent phylogenetic assessment, perhaps because of the relative scarcity of available specimens. The closest approach using molecular datasets, rendered a monophyletic clade that included P. nasutus and P. lativittatus, as separate from sampled members of the tricolor and bilineatus groups (Grazziotin et al. 2012; Figueroa et al. 2016). Ferrarezzi (1993) proposed a phylogenetic hypothesis based on morphology (mostly coloration patterns), and presented a cladogram, with P. nigrilatus as the most derived taxon, and P. concolor as the basal member of the nasutus group. Using the same traits, and including the new species described after Ferrarezzi (1993), we are able to complement that hypothesis (Fig. 6). Thus, we consider P. labiomaculatus to be a sister clade to the group of species exhibiting loss of the 1st temporal scale. P. shawnella sp. nov., together with P. nigrilatus, are the most derived members of this phylogeny.

Figure 6. 

Suggested hypothesis of phylogenetic relationships among species within the Phalotris nasutus group, based on a first proposal by Ferrarezzi (1993). This hypothesis shows a probable change in characters during evolution. *Note that the reduction of 1st temporals is visible in P. labiomaculatus where the 1st temporal is rather small or absent in some specimens (Hamdan et al. 2013). Base map: biomes of the world, according to Olson et al. (2001)

P. shawnella sp. nov. is somewhat morphologically intermediate between P. nigrilatus and P. lativittatus, however hybridization between these two species can be conclusively ruled out. P. nigrilatus and P. lativittatus exhibit widely allopatric ranges, while the occurrence of three individuals showing characters of the new species at two different localities at which neither of these putative “parent species” has ever been recorded stretches plausibility. It is important to add that the coloration of P. nigrilatus and P. shawnella sp. nov. is apparently rather constant (Cacciali et al. 2020). Molecular genetic analyses will be required to reveal whether these two Paraguayan taxa are relicts of a wider ancestral distribution of the group. Currently GenBank has genetic sequences for only two species in the nasutus group (Phalotris nasutus and P. lativittatus), thus efforts still need to be made to collect tissue samples from the remaining species. Unfortunately, snakes are among the least sampled animals, and data on genetics is missing not only within the genus Phalotris, but also for most of the Paraguayan snakes (Cacciali et al. 2019).

The two known localities for P. shawnella sp. nov. (Laguna Blanca and Colonia Volendam) are separated by just 90.5 km, indicating an extremely restricted global range within a single Paraguayan department. Given that this is potentially a forest species and that the area in which it is known to occur is an agricultural matrix undergoing constant alteration, we suggest that this Paraguayan endemic snake is in need of urgent conservation action. A designation of Endangered (B1a,biii) fits the available data, this being a species with an estimated occurrence of less than 5000 km2 and with a severely fragmented range that is known to exist at less than 5 localities and with a continuing decline inferred from the extent and quality of the habitat. Rancho Laguna Blanca, where the holotype was collected, was formerly officially protected (for a period of five years) as a Reserva Natural (Natural Reserve) and given its high herpetological diversity it was recognized as the first Paraguayan Important Area for the Conservation of Amphibians and Reptiles (Smith et al. 2016). However, the property no longer counts with official protection and is currently for sale.

Phalotris nigrilatus and P. shawnella sp. nov. are two endangered (Cacciali et al. 2020), endemic Paraguayan snakes with extremely isolated ranges within San Pedro department. Additional field surveys are urgently required to improve our understanding of the ecological requirements of both taxa so that effective conservation measures can be implemented.

Acknowledgements

We thank Karina Atkinson, Para La Tierra and Malvina Duarte for their support for research activities and their commitment to biodiversity conservation in Paraguay. Henrique Braz and Hugo Cabral provided valuable comments that helped to improve the manuscript. PS and PC are grateful to Consejo Nacional de Ciencia y Tecnología through the PRONII programme for financial support. Marko Fast generously shared his photographs and observations to help confirm the validity of this new taxon. We thank Jeremy Dickens for the photographs of the preserved specimen, and Martha Motte, Nicolás Martínez, and Frederick Bauer, from the Herpetology section of the Museo Nacional de Historia Natural del Paraguay (MNHNP) for their stewardship of an important part of the Paraguayan heritage, and collaborations on scientific research. Particular thanks to Normand David for his expert advice on the presentation of the scientific name. Collection permit issued by Ministerio del Ambiente (MADES), N° 02/13.

References

  • Cacciali P, Mee G, Laing AP, Krause D, McLaughlin C, Montgomery R, Smith P (2020) Morphological re-examination of the endemic Paraguayan snake Phalotris nigrilatus Ferrarezzi, 1993 (Serpentes: Colubridae: Elapomorphini), with notes on its ecology and conservation status. Current Herpetology 39(1): 28–37. https://doi.org/10.5358/hsj.39.28
  • Cope ED (1862) On Elapomorphus, Sympholis, and Coniophanes. Proceedings. Academy of Natural Sciences of Philadelphia 13: 524.
  • Dowling H (1951) A proposed standard system of counting ventrals in snakes. British Journal of Herpetology 1: 97–99.
  • Entiauspe-Neto OM, Tiutenko A, Azevedo W dos S, Abegg AD (2021) Extraordinary claims require extraordinary evidence: On the taxonomic identity of Phalotris cerradensis Silveira, 2020. Revue Suisse de Zoologie 128(1): 53–60. https://doi.org/10.35929/RSZ.0034
  • Figueroa A, McKelvy AD, Grismer LL, Bell CD, Lailvaux SP (2016) A species-level phylogeny of extant snakes with description of a new Colubrid subfamily and genus. PLoS ONE 11(9): e0161070. https://doi.org/10.1371/journal.pone.0161070
  • Grazziotin FG, Zaher H, Murphy RW, Scrocchi G, Benavides MA, Zhang Y, Bonato SL (2012) Molecular phylogeny of the New World Dipsadidae (Serpentes: Colubridae): a reappraisal. Cladistics 28(5): 437–459. https://doi.org/10.1111/j.1096-0031.2012.00393.x
  • Hamdan B, Da Silva Jr NJ, Rodrigues Silva HL, Cintra CED, de Lema T (2013) Redescription of Phalotris labiomaculatus (Serpentes, Dipsadidae, Elapomorphini), with notes on the taxonomic boundaries within the nasutus group. Zootaxa 3693(2): 182–188. https://doi.org/10.11646/zootaxa.3693.2.4
  • Jansen M, Köhler G (2008) A new species of Phalotris from the eastern lowlands of Bolivia (Reptilia, Squamata, Colubridae). Senckenbergiana Biologica 88: 103–110.
  • Jarvis A, Reuter HI, Nelson A, Guevara E (2008) Hole-filled SRTM for the globe Version 4. http://srtm.csi.cgiar.org [available from the CGIAR-CSI SRTM 90m, accessed 15 January 2020]
  • Olson DM, Dinerstein E, Wikramanayake ED, Burgess ND, Powell GVN, Underwood EC, D’Amico JA, Itoua I, Strand HE, Morrison JC, Loucks CJ, Allnutt TF, Ricjetts TH, Kura Y, Lamoreux JF, Wettengel WW, Hedao P, Kassem KR (2001) Terrestrial ecoregions of the world: A new map of life on Earth. Bioscience 51(11): 933–938. https://doi.org/10.1641/0006-3568(2001)051[0933:TEOTWA]2.0.CO;2
  • Peters JA (1964) Dictionary of Herpetology. Hafner, NY& London, 488 pp.
  • Puorto G, Ferrarezzi H (1993) Uma nova espécie de Phalotris Cope, 1862, com comentários sobre o grupo bilineatus (Serpentes: Colubridae: Xenodontinae). Memorias do Instituto Butantan 55: 39–46.
  • Silveira Vasconcelos T, Gomes dos Santos T (2009) Reptilia, Serpentes, Dipsadidae, Phalotris lativittatus: Distribution extension and geographic distribution map. Check List 5(1): 5–7. https://doi.org/10.15560/5.1.5
  • Smith P, Atkinson K, Brouard JP, Pheasey H (2016) Reserva Natural Laguna Blanca, Departamento San Pedro: Paraguay’s first important area for the conservation of amphibians and reptiles? Russian Journal of Herpetology 23: 25–34. https://doi.org/10.30906/1026-2296-2016-23-1-25-34
  • Zaher H (1999) Hemipenial morphology of the South American xenodontine snakes: with a proposal for a monophyletic Xenodontinae and a reappraisal of colubroid hemipenes. Bulletin of the American Museum of Natural History 240: 1–168. http://hdl.handle.net/2246/1646

Appendix 1

Examined specimens

Phalotris nigrilatus (11): PARAGUAY, SAN PEDRO DEPARTMENT: Colonia Primavera (NHM 1955.1.5.99, 1955.1.6.2–3, 1956.1.3.48, 1956.1.16.39–40, 1958.1.3.30, 1960.1.3.5–8).

Phalotris multipunctatus (2): Rancho Laguna Blanca (CZPLT 1138, 1145).

Phalotris shawnella sp. nov. (3): Rancho Laguna Blanca (CZPLT 594), one live topotype from Rancho Laguna Blanca and photographs of a third individual from Colonia Volendam.

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