Research Article |
Corresponding author: Santiago R. Ron ( santiago.r.ron@gmail.com ) Academic editor: Angelica Crottini
© 2020 Santiago R. Ron, Julio Carrión, Marcel A. Caminer, Yerka Sagredo, María J. Navarrete, Jhael A. Ortega, Andrea Varela-Jaramillo, Gabriela A. Maldonado-Castro, Claudia Terán.
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:
Ron SR, Carrión J, Caminer MA, Sagredo Y, Navarrete MJ, Ortega JA, Varela-Jaramillo A, Maldonado-Castro GA, Terán C (2020) Three new species of frogs of the genus Pristimantis (Anura, Strabomantidae) with a redefinition of the P. lacrimosus species group. ZooKeys 993: 121-155. https://doi.org/10.3897/zookeys.993.53559
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A new phylogeny for the Pristimantis lacrimosus species group is presented, its species content reviewed, and three new species described from the eastern slopes of the Ecuadorian Andes. Our phylogeny includes, for the first time, samples of P. aureolineatus, P. bromeliaceus, and P. lacrimosus. The morphology of hyperdistal subarticular tubercles is also assessed among 21 species of Pristimantis. The P. lacrimosus species group is composed of 36 species distributed in the Chocó, Guiana, and Amazon regions of tropical South America with a single species reaching Central America. Ancestral area reconstruction indicates that, despite its high diversity in the Amazon region, the P. lacrimosus group originated in the Pacific basin, Chocó region of Ecuador and Colombia. Pristimantis amaguanae sp. nov. is most closely related to P. bromeliaceus. It differs from P. bromeliaceus by being smaller, having transversal dark bands in the hindlimbs (absent or faint in P. bromeliaceus) and the absence of discoidal fold (present in P. bromeliaceus). Pristimantis nankints sp. nov. and P. romeroae sp. nov. are part of a clade of predominantly light-green frogs that includes P. acuminatus, P. enigmaticus, P. limoncochensis, and P. omeviridis. Pristimantis nankints sp. nov. and P. romeroae sp. nov. can be distinguished from all of them by the presence of a dark dorsolateral stripe that borders a light green band on a green background. Hyperdistal tubercles are present in all examined species of the P. lacrimosus species group and its sister clade. Species with hyperdistal tubercles are characterized by having relatively long terminal phalanges and narrow T-shaped expansion at the end of the terminal phalange. We discuss the phylogenetic distribution of these characters and their potential diagnostic significance.
Amazon, Andes, Brachycephaloidea, morphology, phalanges, phylogeny, Pristimantis amaguanae sp. nov., Pristimantis nankints sp. nov., Pristimantis romeroae sp. nov., subarticular tubercles, systematics, taxonomy, Terrarana
With 540 species Pristimantis is the most diverse vertebrate genus and represents a majority of the formally described anuran diversity in the tropical Andes of Colombia and Ecuador (
One phenotypically distinctive group of Pristimantis is the P. lacrimosus group. Species of this group are frequently found in bromeliad plants and have broad and flattened heads with acuminate snouts (
During fieldwork in cloud forests of the Amazon Basin of Ecuador, field teams from Museo de Zoología at Catholic University of Ecuador found three distinctive species that belong to the Pristimantis lacrimosus species group. Herein we describe them and present a new phylogeny for the group including, for the first time, P. aureolineatus, P. bromeliaceus, and P. lacrimosus.
The format for the descriptions follows
Fingers and toes are numbered preaxially to postaxially from I to IV and I to V, respectively. Relative lengths of toes III and V were determined by adpressing them against toe IV; lengths of fingers I and II were compared by appressing them to each other. While describing the hands and feet of the new species, we noticed the presence of an additional distal subarticular tubercle. These tubercles were recently named by
Palmar and plantar surfaces of Pristimantis romeroae sp. nov. and X-ray of the hand A ventral view of the left foot B ventral view of left hand C X-ray of the left hand. Holotype (
Subarticular tubercles underly articulations between phalanges (
X-ray images of the left hand of adult Pristimantis romeroae sp. nov. and P. crenunguis. The ratios of the length of the ultimate and penultimate phalanges of finger III are shown. Dashed lines indicate the border of soft tissues; continuous lines indicate the edge of bones. Pristimantis romeroae sp. nov.,
We estimated the phylogenetic relationships of the new species based on DNA sequences of mitochondrial genes 12S rRNA (12S), 16S rRNA (16S), NADH dehydrogenase subunit 1 (ND1), their flanking tRNAs and the nuclear gene Recombination activating gene 1 (RAG-1). DNA was extracted from muscle or liver tissue preserved in 95% ethanol, using standard guanidine thiocyanate extraction protocols. We used a polymerase chain reaction (PCR) to amplify DNA fragments.
The primers used for the 12S amplification were obtained from
Our matrix included 74 newly generated sequences of Pristimantis (Table
GenBank accession numbers for DNA sequences used in the phylogenetic analyses.
Species | Voucher | 12S | 16S | RAG-1 | ND1 |
---|---|---|---|---|---|
P. acerus | KU 217786 | EF493678.1 | EF493678.1 | NA | NA |
KU 217830 | NA | EF493696.1 | EF493432.1 | NA | |
P. altamazonicus | KU 215460 | EF493670.1 | EF493670.1 | NA | NA |
P. amaguanae sp. nov. |
|
MT636506 | MT636529 | MT635622 | MT635661 |
P. angustilineatus | UVC 15828 | NA | JN371034.1 | NA | NA |
P. appendiculatus | KU177637 | EF493524.1 | EF493524.1 | NA | NA |
P. aureolineatus |
|
MT636509 | MT636530 | MT635626 | NA |
P. boulengeri | MHUAA 8951 | NA | KU724435.1 | NA | NA |
P. brevifrons | nrps 0059 | JN991498.1 | JN991433.1 | NA | NA |
P. bromeliaceus |
|
MT636505 | MT636527 | MT635618 | MT635659 |
|
MT636512 | MT636523 | NA | MT635669 | |
P. calcarulatus | KU 177658 | EF493523.1 | EF493523.1 | NA | NA |
P. cedros | MZUTI 1713 | NA | KT210155.1 | NA | NA |
P. cf. mendax | MTD 45080 | EU186659.1 | EU186659.1 | NA | NA |
P. crucifer | KU 177733 | EU186736.1 | EU186718.1 | NA | NA |
P. diadematus | KU 221999 | EU186668.1 | EU186668.1 | NA | NA |
KU179090 | EF493522.1 | EF493522.1 | NA | NA | |
P. dorsopictus | MHUAA7638 | KP082864.1 | KP082874.1 | NA | NA |
P. ecuadorensis | CJ 5350 | KX785339 | KX785343 | NA | KX785347 |
CJ 5351 | KX785340 | KX785344 | NA | KX785348 | |
P. enigmaticus |
|
MT636513 | MT636520 | MT635636 | MT635670 |
P. galdi |
|
EU186670.1 | EU186670.1 | EU186746 | NA |
P. glandulosus | KU 218002 | EF493676.1 | EF493676.1 | NA | NA |
P. imitatrix | KU 215476 | EF493824.1 | EF493667.1 | NA | NA |
P. inusitatus | KU 218015 | EF493677.1 | NA | NA | NA |
P. jaguensis | MHUAA 7249 | KP082862.1 | KP082870.1 | NA | NA |
P. jorgevelosai | JDL 26123 | NA | DQ195461.1 | NA | NA |
P. lacrimosus |
|
NA | MT636518 | MT635629 | MT635667 |
|
NA | MT636517 | MT635633 | NA | |
|
NA | MT636524 | MT635623 | MT635671 | |
|
NA | MT636516 | MT635632 | NA | |
P. limoncochensis |
|
NA | MT636525 | MT635627 | MT635665 |
|
MN128395 | MT636532 | MT635620 | NA | |
P. melanogaster | EF493826.1 | EF493664.1 | NA | NA | |
P. mindo | MZUTI 1382 | NA | KF801584.1 | NA | NA |
MZUTI 1381 | NA | KF801583.1 | NA | NA | |
|
NA | MT636522 | MT635630 | MT635668 | |
MZUTI 1756 | NA | KF801581.1 | NA | NA | |
|
MT636508 | MT636531 | MT635625 | MT635664 | |
P. moro | AJC 1860 | JN991520.1 | JN991454.1 | JQ025191.1 | NA |
AJC 1753 | JN991519.1 | JN991453.1 | JQ025192.1 | NA | |
P. nankints sp. nov. |
|
NA | MT636514 | MT635635 | NA |
P. nyctophylax | KU 177812 | EF493526.1 | EF493526.1 | NA | NA |
|
NA | MT636519 | MT635621 | MT635660 | |
P. omeviridis |
|
MN128400 | MK881398 | MK881312 | MT635658 |
|
NA | EU13057 | MT635619 | NA | |
P. orcesi | KU 218021 | EF493679.1 | EF493679.1 | NA | NA |
P. ornatissimus | MZUTI 4798 | KU720464 | KU720463 | NA | KU720480 |
MZUTI 4806 | KX785337 | KX785341 | NA | KX785345 | |
MZUTI 4807 | KX785338 | KX785342 | NA | KX785346 | |
P. pahuma | MZUTI 493 | NA | KT210158.1 | NA | NA |
P. platydactylus | MNCN 5524 | FJ438811.1 | EU192255.1 | NA | NA |
P. pulvinatus | KU 181015 | EF186741.1 | EF186723.1 | NA | NA |
P. pycnodermis | KU 218028 | EF493680.1 | EF493680.1 | NA | NA |
P. romeroae sp. nov. |
|
MT636507 | MT636528 | MT635624 | MT635662 |
P. rubicundus |
|
NA | MT372670 | MT372613 | NA |
P. schultei | KU 212220 | EF493681.1 | EF493681.1 | NA | NA |
P. subsigillatus | KU 218147 | EF493525.1 | EF493525.1 | NA | NA |
|
NA | MT636521 | MT635628 | MT635666 | |
MECN 10117 | NA | KF801580.1 | NA | NA | |
P. urani | MHUAA 7471 | NA | KU724442.1 | NA | NA |
P. w-nigrum |
|
MT636510 | MT372703 | MT372600 | MT372569 |
|
NA | MT372704 | MT372603 | MT372571 | |
|
NA | MT372691 | NA | MT635663 | |
Pristimantis sp. | ROM 43978 | EU186678.1 | EU186678.1 | NA | NA |
KU 291702 | EF493351.1 | EF493351.1 | NA | NA | |
|
NA | MT636515 | MT635634 | NA | |
|
MT636511 | MT636526 | MT635631 | NA |
The new sequences were assembled in Geneious 9.0 and then exported to Mesquite 3.61 (
Most species of the Pristimantis lacrimosus group occur in the Amazon and Pacific basins. To determine the biogeographic origin of the group, we carried out ancestral state reconstruction. Regions were coded as a binary character (Pacific or Amazon) and the reconstruction employed maximum likelihood as optimality criterion. The analysis was carried out in Mesquite 3.61 (
The phylogeny (Fig.
Phylogenetic relationships of the Pristimantis lacrimosus species group. Maximum likelihood tree for genes 12S, 16S, ND1 and RAG-1. SH-aLRT support (above) and non-parametric bootstrap support (below) are shown as percentages on branches. Asterisks indicate support values of 100 (bootstrap). Voucher number, species, and locality of the samples are shown next to each terminal; country is indicated by the following abbreviations: COL = Colombia, EC = Ecuador, GUY = Guyana, PAN = Panama, PER = Peru, VEN = Venezuela. The new species are shown with bold green characters. Changes in species identifications relative to the GenBank database are shown with red. Photographs show five species of the clade of green species and P. amaguanae sp. nov.. Outgroup is not shown.
We also found strong support (SH-aLRT = 94, bootstrap = 74) for a sister clade relationship between the P. lacrimosus group (as redefined below) and a clade composed of 11 species including P. appendiculatus, P. calcarulatus, P. cedros, P. jaguensis, P. pycnodermis, and P. orcesi. Within the P. lacrimosus species group, Pristimantis amaguanae sp. nov. is most closely related to P. bromeliaceus and an undescribed species from Bombuscaro, Podocarpus National Park, Ecuador. Branch lengths in the phylogeny and its morphological distinctiveness indicate that P. amaguanae sp. nov. is evolutionarily independent from P. bromeliaceus and the undescribed species from Bombuscaro. Uncorrected p-genetic distances (gene 16S) between P. amaguanae sp. nov. and its sister clade range between 13.0 and 13.8%. Pristimantis nankints sp. nov. is sister to an undescribed species from Sardinayacu, Sangay National Park, Ecuador. Their genetic distance is 2.7%. Both species are sister to P. romeroae sp. nov. from Napo Province. They are separated by distances of 6.9 (P. sp.) and 7.0% (P. nankints sp. nov.) These three species are sister to a clade composed by P. jorgevelosai, P. enigmaticus, P. limoncochensis, P. omeviridis, and P. tantanti.
The reconstruction of ancestral basin indicates that the group originated in the Pacific basin with a single colonization event to the Amazon basin (Fig.
Ancestral reconstruction for geographic basin (Pacific vs. Amazon) in the Pristimantis lacrimosus species group. Reconstructions were based on maximum likelihood inference. Pie charts at nodes represent conditional probabilities for the Pacific (black) and Amazon (green) basins. The asterisk indicates significant support for the Pacific basin as ancestral area for the most recent common ancestor of the P. lacrimosus species group. White circles indicate equivocal state, striped circles indicate distribution outside the Pacific or Amazonian basins (coded as missing data).
Most examined species of Pristimantis lack hyperdistal tubercles (Table
Phalange morphometry and hyperdistal tubercle condition in several species of Pristimantis. Species of the Pristimantis lacrimosus species group are shown in bold. Species are ordered according to the relative length of the terminal phalanges (from low to high, terminal/penultimate). The five lowest T-width/terminal values are shown with italics. Note that species of the P. lacrimosus species group are characterized by having longer terminal phalanges, narrower T-expansions at the end of the terminal phalange, and hyperdistal tubercles. Hyperdistal tubercles were coded as “present” when they were similar in size to other hyperdistal tubercles in the same finger or toe.
|
Species | Terminal/ penultimate | T-width/ terminal | Hyperdistal tubercle |
---|---|---|---|---|
56506 | P. crenunguis | 0.463 | 0.980 | absent |
40057 | P. buckleyi | 0.467 | 0.597 | absent |
2308 | P. unistrigatus | 0.473 | 0.574 | absent |
63435 | P. bicantus | 0.485 | 0.578 | absent |
43313 | P. quinquagesimus | 0.535 | 0.921 | absent |
66850 | P. condor | 0.550 | 0.608 | absent |
39122 | P. lanthanites | 0.558 | 0.652 | absent |
26209 | P. appendiculatus | 0.574 | 0.538 | absent |
49633 | P. achatinus | 0.601 | 0.461 | absent |
61831 | P. pycnodermis | 0.626 | 0.455 | absent |
47731 | P. chomskyi | 0.670 | 0.583 | absent |
66559 | P. eriphus | 0.732 | 0.539 | present |
66881 | P. katoptroides | 0.743 | 0.495 | present |
39763 | P. orcesi | 0.752 | 0.754 | present |
67662 | P. crucifer | 0.757 | 0.307 | absent |
65062 | P. phoxocephalus | 0.772 | 0.494 | absent |
41121 | P. romeroae sp. nov. | 0.828 | 0.317 | present |
30954 | P. limoncochensis | 0.831 | 0.294 | present |
71457 | P. nankints sp. nov. | 0.839 | 0.314 | present |
73812 | P. enigmaticus | 1.044 | 0.500 | present |
56418 | P. acuminatus | 1.060 | 0.293 | present |
Content. We present a new definition of the group based in our phylogeny and recent taxonomic reviews. We define the P. lacrimosus species group to include all species descendant of the most recent common ancestor of P. eremitus and P. lacrimosus (Fig.
The group contains 36 described species: P. acuminatus (
Holotype.
English: Amaguaña’s Rain Frog. Spanish: Cutín de Amaguaña.
A species of Pristimantis characterized by the following combination of characters: (1) skin on dorsum shagreen with conical tubercles, skin on venter areolate with light green warts on the chest; discoidal fold absent; dorsolateral folds absent (Fig.
In this section, coloration refers to live individuals unless otherwise noticed. The coloration of Pristimantis amaguanae resembles that of P. bromeliaceus and P. petersi (Fig.
Adult female (
Skin on dorsum shagreen with scattered tubercles; dorsolateral folds absent; skin on lower flanks and belly areolate with scattered tubercles; skin on throat and chest smooth; discoidal fold absent; skin in upper cloacal region shagreen, wrinkled ventrally, with several tubercles below the cloacal sheath. Forearms slender; conical ulnar tubercles present along outer edge of forearm; all digits bearing pads and discs, broadly expanded and rounded but those of fingers II–IV clearly larger than that on thumb; fingers bearing narrow lateral fringes; relative lengths of fingers I < II < IV < III; subarticular tubercles single, well defined, round in ventral and lateral view; hyperdistal subarticular tubercles present in all fingers; several supernumerary tubercles at base of fingers present, distinct; palmar tubercle bifid, approximately 1.5 size of ovoid thenar tubercle (Fig.
Hindlimbs slender; upper surfaces of hindlimbs smooth; posterior surfaces of thighs smooth, ventral surfaces of thighs slightly areolate; heel bearing low conical tubercles; inner surface of tarsus bearing small, low tubercles; toes with lateral fringes; webbing between toes absent; discs on toes expanded, elliptical, as large as those on fingers; all toes having pads surrounded by circumferential grooves; relative lengths of toes: I < II < III < V < IV; subarticular tubercles rounded, simple; hyperdistal subarticular tubercles present; plantar surface with supernumerary tubercles; inner metatarsal tubercle prominent, ovoid approximately five times of rounded outer metatarsal tubercle (Fig.
Color of holotype in preservative. (Fig.
Color of holotype in life. (Fig.
In this section, variation refers to a preserved male
Color in life (based on digital photographs; Fig.
This species is only known from the type locality in Provincia de Pastaza, Ecuador at 430 m above sea level (Fig.
Known distribution of the three new species and type localities of P. paululus, P. petersi, and P. bromeliaceus. Localities are based on specimens deposited at Museo de Zoología of Pontificia Universidad Católica del Ecuador and from Lynch (1974), Lynch (1979), and Lynch and
We recommend assigning Pristimantis amaguanae to the Endangered Red List category according to the B2ab(iii) criteria (based on
The specific name amaguanae is a noun in the genitive case and is a patronym for Tránsito Amaguaña, a leading female figure of the indigenous movement in Ecuador. In 1930 she helped to form the first indigenous organization in Ecuador and during all her life she fought for equality and justice for Ecuadorian poor people.
Holotype.
English: Nankints Rain Frog. Spanish: Cutín de Nankints.
A species of Pristimantis characterized by the following combination of characters: (1) skin on dorsum shagreen, skin on venter areolate with scattered warts, smooth on throat; discoidal fold absent; dorsolateral folds absent; (2) tympanic membrane and tympanic annulus present, upper edge of tympanic annulus covered by supratympanic fold; (3) snout short, protruding in lateral profile, acuminate in dorsal view, with rostral papilla; (4) upper eyelid without conical tubercles; cranial crests absent; (5) dentigerous processes of vomers present, prominent, oblique; (6) male having vocal slits, nuptial pads absent; (7) finger I shorter than finger II; discs of digits moderately expanded, rounded; (8) fingers bearing narrow lateral fringes; hyperdistal subarticular tubercles present; (9) ulnar and tarsal tubercles present, those on the tarsus are flattened and low, nearly inconspicuous; (10) heel without conical tubercles; inner tarsal fold present; (11) inner metatarsal tubercle prominent, elliptical, approximately 3× as large as rounded, conical outer metatarsal tubercle; outer metatarsal tubercle small, rounded; supernumerary plantar tubercles inconspicuous (Fig.
(Fig.
Live adult individuals of the clade of green Pristimantis within the P. lacrimosus complex and their closest relatives A Pristimantis acuminatus,
Adult female (
Skin on dorsum shagreen; dorsolateral folds absent; skin on belly and posterior half of chest areolate with scattered warts; skin on anterior half of chest and throat smooth; discoidal fold absent; skin in upper cloacal region shagreen. Forearms slender with a row of four conical ulnar tubercles in outer edge of forearm; fingers large and slender, all with round discs; fingers bearing narrow lateral fringes; relative lengths of fingers I < II < IV < III; subarticular tubercles single, well defined, round in ventral view; hyperdistal subarticular tubercles present in all fingers; supernumerary palmar tubercles present, distinct; palmar tubercle bifid, 2× size of ovoid thenar tubercle (Fig.
Hindlimbs slender; tibia length ca. 50% of SVL; upper surfaces of hindlimbs smooth; foot length ca. 46 % of SVL, posterior surfaces of thighs smooth, ventral surfaces of thighs slightly areolate; knee and heel lacking tubercles; inner surface of tarsus lacking tubercles; toes bearing narrow lateral fringes; webbing between III and IV toes present at the base; discs on toes broadly expanded, rounded, relatively smaller than fingers; all toes having pads surrounded by circumferential grooves; relative lengths of toes: I < II < III < V < IV; subarticular tubercles rounded; hyperdistal subarticular tubercles present in all toes; plantar surface with inconspicuous supernumerary tubercles; inner metatarsal tubercle prominent, elliptical, approximately three times as large as rounded, conical outer metatarsal tubercle (Fig.
Color of holotype in preservative. (Fig.
Color of holotype in life. (Fig.
(Fig.
Morphometric variables of Pristimantis nankints sp. nov. and Pristimantis romeroae sp. nov. Mean ± SD is given with range in parentheses. All measurements are in millimeters.
Variable | P. nankints sp. nov. | P. romeroae sp. nov. | ||
male | female | male | female | |
n = 1 | n = 2 | n = 1 | n = 3 | |
Snout-vent length | 19.6 | 29.4 ± 2.2 (27.8–30.9) | 23.8 | 32.0 ± 1.6 (31.1–33.8) |
Tibia length | 10.4 | 13.3 ± 0.2 (13.2–13.5) | 9.9 | 14.6 ± 0.6 (14.2–15.2) |
Foot length | 10.8 | 14.5 ± 0.6 (14.1–14.9) | 11.1 | 15.8 ± 0.3 (15.6–16.1) |
Head length | 7.0 | 10.7 ± 1.0 (10.0–11.4) | 8.2 | 11.4 ± 0.6 (10.8–12.0) |
Head width | 6.3 | 10.3 ± 0.4 (10.0–10.6) | 7.7 | 11.3 ± 0.4 (11.0–11.7) |
Eye diameter | 2.6 | 2.8 ± 0.2 (2.7–3.0) | 2.8 | 3.2 ± 0.3 (2.9–3.4) |
Tympanum diameter | 1.8 | 2.3 ± 0.1 (2.3–2.4) | 2.3 | 2.8 ± 0.5 (2.4–3.3) |
Color in life (based on digital photographs of an adult male
Pristimantis nankints has been recorded at one locality in the eastern Andean slopes of Ecuador, Provincia Morona Santiago, Cordillera del Cutucú, 1364–1413 m above sea level (Fig.
Specimens were found at night along crystalline creek surrounded by secondary forest. The holotype was perching on a leaf 2 m above the ground, next to the stream; after capture, while in the plastic bag, the female deposited 22 eggs. The adult male was collected on secondary forest, on a terrestrial bromeliad. The female paratype was perching on a leaf 30 cm above the ground.
Pristimantis nankints distribution area is a mosaic of forest and deforested areas (based on
The species name is a noun in apposition that refers to Nankints, a small hamlet in Cordillera del Cóndor, Ecuador, that used to be inhabited by Shuar native Americans. Its dwellers were violently evicted and Nankints was destroyed in 2016 to establish a mining camp. Large scale mining projects generate widespread deforestation and pollution in the Andes. The species name is a tribute to Ecuadorian people who have resisted mining activities in defense of the environment. Nankints is a shuar word that means spear.
Holotype. (Figs
Variation in preserved specimens of Pristimantis romeroae sp. nov. From left to right, first and second rows:
Paratypes (3). Provincia de Napo:
English: Romero’s Rain Frog. Spanish: Cutín de Romero.
A species of Pristimantis characterized by the following combination of characters: (1) skin on dorsum shagreen, skin on venter areolate with scattered warts; discoidal fold absent; dorsolateral folds absent; (2) tympanic membrane and tympanic annulus present, upper edge of tympanic annulus covered by supratympanic fold; (3) snout short, truncate in dorsal view, slightly protruding in lateral profile, with small rostral papilla; (4) upper eyelid with several small tubercles; cranial crests absent; (5) dentigerous processes of vomers present, prominent, moderately oblique; (6) male having vocal slits, nuptial pads present on finger I; (7) finger I slightly shorter than finger II; discs of digits expanded, truncate; (8) fingers with lateral fringes; hyperdistal subarticular tubercles present; (9) ulnar tubercles absent, tarsal tubercles present, subconical, conspicuous; (10) heel with one, nearly inconspicuous, small subconical tubercle or without tubercles; inner tarsal fold absent; (11) inner metatarsal tubercle prominent, elliptical, approximately three times as large as rounded, conical outer metatarsal tubercle; supernumerary plantar tubercles present (Fig.
In this section, coloration refers to preserved individuals (Fig.
Adult female (
Skin on dorsum and flanks shagreen; dorsolateral folds absent; skin on belly and posterior half of chest areolate with scattered warts; skin on throat and anterior half of chest smooth; discoidal fold absent; skin in upper cloacal region smooth. Forearms slender with three ill-defined, low ulnar tubercles in distal, medial and proximal outer edge of forearm; fingers large and slender, all fingers with pads surrounded by circumferential grooves, truncate discs; bearing narrow lateral fringes; relative lengths of fingers I < II < IV < III; subarticular tubercles single, round in ventral and lateral view; hyperdistal subarticular tubercles present; bearing few, inconspicuous, low supernumerary tubercles, palmar tubercle bifid, twice the size of elliptical thenar tubercle (Fig.
Hindlimbs slender; tibia length ca. 50% of SVL; upper surfaces of hindlimbs smooth; foot length ca. 45 % of SVL, posterior surfaces of thighs shagreen, ventral surfaces of thighs smooth; knee and heel lacking tubercles; inner surface of tarsus lacking tubercles; toes bearing narrow lateral fringes; webbing between toes absent; discs on toes broadly expanded, truncate, the same size than fingers; all toes having pads surrounded by circumferential grooves; relative lengths of toes: I < II < III < V < IV; subarticular tubercles rounded, simple; hyperdistal subarticular tubercles present; plantar surface with numerous indistinct supernumerary tubercles; inner metatarsal tubercle prominent, elliptical, approximately 3 times the size of rounded, conical outer metatarsal tubercle (Fig.
Color of holotype in preservative. (Fig.
Color of holotype in life. Unknown but presumably green, similar to its most closely relatives (e.g., P. nankints, P. enigmaticus) which have a similar clear coloration in preservative (Figs
(Fig.
Color in life: unknown but presumably green (see description of the holotype).
Pristimantis romeroae is known from one locality at the eastern Andean slopes of Ecuador, Provincia de Napo, on the SSE slope of the Sumaco volcano, 1602 m above sea level (Fig.
In 2008, one year before the specimens were collected, the type locality was at a distance of < 1 km from agricultural deforested areas (based on
The species name is a noun in the genitive case and is a patronym for Giovanna Romero, an Ecuadorian botanist and SRR’s wife. For almost two decades, she has supported SRR’s research in countless ways and this is a long-overdue tribute.
Subarticular tubercles are round dermal protuberances, below the articulations of phalanges, on the underside of the hands and feet of anurans. According to the most recent comprehensive reviews of morphological characters of Pristimantis (
The available information on the phylogenetic distribution of hyperdistal tubercles and the morphology of the terminal phalanges suggest that they have phylogenetic signal and diagnostic value. Hyperdistal tubercles are present in all examined species of the P. lacrimosus species group (ten species: Table
Interestingly, our results suggest that the presence of hyperdistal tubercles is linked to two osteological characters of the terminal phalanges (Table
The correlation between the presence of hyperdistal tubercles and the morphology of the terminal phalanges has not been tested. We suspect that in species with short ultimate phalanges, like P. crenunguis (Fig.
Our reconstruction of ancestral basin indicates that the P. lacrimosus species group originated in the Chocoan forests of the Pacific basin of Ecuador and Colombia. This result was unexpected because, by far, most species of the group occur in the Amazon basin (26 described species out of 36). Our reconstruction suggests that the Amazon basin was colonized on a single event. The paucity of colonization events across the Andes demonstrates the pivotal role of the Andean barrier in the diversification of Pristimantis. There is a single colonization event from the Amazon Basin to the Chocoan forests with P. moro. Because P. moro is also distributed in Central America, we suspect that its presence in the Chocoan forest is a result of a colonization from central America instead of colonization across the Andes. The Amazon basin was also the origin of P. jorgevelosai, a species distributed in the Magdalena river basin and embedded in an otherwise Amazonian clade (Fig.
Our biogeographic reconstruction suggests that the P. lacrimosus species group had higher diversification rates in the Amazon basin relative to the Chocó region. There are two clades inhabiting the Chocoan region. One of them is older than the Amazonian clade and yet it only has four species. The second clade is sister to the Amazonian clade. Although both clades have the same age, the Chocoan clade has only four species compared to 19 species in the Amazonian clade. These differences in diversification rates are inconsistent with the time-for-speciation hypothesis, which predicts the highest richness in first colonized regions (
Ana Belén Carrillo helped with laboratory work. For specimen collection, locality data, and field assistance, we are indebted to Diego Almeida, Fernando Ayala, Edwin Carrillo, Galo Díaz, Ricardo Gavilanes, Yadira Mera, Jefferson Mora, Darwin Núñez, Kunam Nusirquia, Diego Paucar, Raúl E. Ruiz, and Elicio Tapia. Research and collecting permits were issued by the Ministerio de Ambiente del Ecuador (003-17 IC-FAU-DNB/MA, 008-09 IC-FAU-DNB/MA and MAE-DNB-CM-2015-0025). Field and laboratory work in Ecuador were funded by Secretaría Nacional de Educación Superior, Ciencia, Tecnología e Innovación del Ecuador SENESCYT (Arca de Noé initiative; SRR and Omar Torres principal investigators) and a grant from Pontificia Universidad Católica del Ecuador, Dirección General Académica. We thank Santiago Guamán, Diego Paucar, and Fernando Ayala for assisting access to the
Pristimantis petersi. ECUADOR: PROVINCIA NAPO: Cantón: Archidona. Cocodrilos, Cocodrilo Station (0.6545°S, 77.7848°W) 1732 m, (
Pristimantis bromeliaceus. ECUADOR: PROVINCIA MORONA SANTIAGO: Cantón: Gualaquiza. Chinguida (3.2263°S, 78.7105°W) 1930 m (
Pristimantis paululus. ECUADOR: PROVINCIA NAPO. Jatun Sacha Biological Reserve (1.05°S, 77.6000°W) 388 m (