Chiroderma doriae Thomas, 1891

Garbino, Guilherme S. T., Lim, Burton K. & Tavares, Valéria Da C., 2020, Systematics of big-eyed bats, genus Chiroderma Peters, 1860 (Chiroptera: Phyllostomidae), Zootaxa 4846 (1), pp. 1-93 : 31-37

Chiroderma doriae Thomas, 1891

Synonyms: See under subspecies.

Type Material. The type of Chiroderma doriae , by original designation, is specimen BMNH 44.9.2.6 (skin) and BMNH 49.8.16.29 (skull and mandible). The holotype is an adult of undetermined sex, but possibly female, as there is no vestige of scrotal sac on the skin. The skin was stitched longitudinally along the dorsum and probably for this reason the descriptions described the dorsal stripe as absent ( Dobson 1878, misdentified as C. villosum ; Vieira 1942). The left ear, as well as the right tarsus and metatarsus, have been lost, but the right calcar and the tibia are still attached to the skin. Interocular stripes are evident, but the color of the skin appears to be slightly faded. The genal pair of facial stripes is less conspicuous, and the stripe on the right side is more evident than on the left. Part of the medial uropatagium is torn.

The skull is damaged, and the region posterior to the mesopterygoid fossa, i.e. the basioccipital, occipital, and the posterior part of the braincase are missing. The upper dental arcade is complete. The right zygomatic arch is broken, and the root of the right upper canine is exposed. Part of the palate is also broken. The inner upper incisors have convergent tips, almost touching each other. The mandible and lower dentition are in good condition, except for the left angular process, which is missing.

Information on the label indicates “Minas Geraes” as the locality and that the type was obtained from Parzudaki , referring to Charles Parzudaki and his adopted son Emile , two active dealers in natural history specimens in Paris. As Charles and Emile probably never collected in South America ( Gouraud et al. 2016), it is not possible to determine the collector or to estimate a more precise locality for the specimen.

Distribution and Habitat. See under Subspecies.

Description and Comparisons. Dorsal pelage is pale brown in most specimens of C. d. doriae , but some have dark brown pelage. In C. d. vizottoi the dorsal pelage is pale buff ( Fig.18 ). Dorsal hairs are tricolored; the base is dark brown, the middle is buff, and the tip is pale brown (C. d. doriae ) or pale buff (C. d. vizottoi ). Two pairs of interocular and genal stripes are present, wide, and formed by entirely white hairs. A median dorsal stripe is present. The stripe is conspicuous in 25 of the 29 (86%) C. d. doriae examined, and usually extends from the interscapular region to the posterior extremity of the rump. One C. d. doriae (ZUFMS 395) has the dorsal stripe beginning on the nape. The ear and tragus are yellowish at the bases, as well as is the margin of the ear. The remainder of the ear is brownish. The spear of the noseleaf is simple-tipped and the lateral borders of the horseshoe are paler than the medial portion and spear.

Chiroderma doriae has the second largest cranium among Chiroderma species, smaller only than C. improvisum ( Tables 7 and 8). There is some overlap among the measurements of small C. d. doriae and large C. salvini . Measurements of C. d. vizottoi broadly overlap with those of C. villosum , C. salvini , and large C. scopaeum ( Tables 7 and 8). The braincase is low in C. d. doriae , relative to the length of the skull, and less globose than in the other species (except for C. improvisum ; Figs. 19 , 20 ). In C. d. vizottoi , the braincase is relatively higher and more globose than in the nominal subspecies. A sagittal crest was present in every specimen of C. d. doriae we examined (n=71), being conspicuous in 41 (57%), moderate in 25 (35%), and low or vestigial in 5 (7%). In C. d. vizottoi , the sagittal crest was present in all specimens (n=11), conspicuous in ten (90.9%) and moderate or low in one (9.1%). The nasal notch is long, extending well behind the anterior rim of the orbits. The post-orbital processes are moderately developed, more so than in gorgasi and trinitatum , but less than in salvini , scopaeum and villosum ( Fig. 19 ).

The posterior palatine process is absent in 51 (78%) of the 65 specimens of C. d. doriae we examined. When present, the palatine process is small and inconspicuous, except for three specimens (4.6%), in which this structure was conspicuous. In C. d. vizottoi , the palatine process was absent in five of nine specimens in our sample. The posterior border of the palate is U-shaped, differing from other species of Chiroderma , which have an even posterior border. Paraoccipital processes are present in C. d. doriae . When skull and mandible are in occlusion, a lateral gap is formed, as in C. salvini , C. scopaeum , C. gorgasi , and C. trinitatum ( Fig. 9 ).

The I1s have converging tips that contact each other in most specimens. One (ZUFMS 395) had parallel I1s, with no contact. The P3, in occlusal view, is wider (buccolingually) than long (mesiodistally). P3 touches C, but does not touch P4 (in the similar-sized C. improvisum , P3 and P4 are in contact; see Fig. 19 ). The P4 has a welldeveloped disto-lingual cingulum (relatively less-developed in the other species). The mandible is robust, with the condylar processes clearly above the toothrow plane, or at approximately the same level. The coronoid process clearly is higher than the tip of the lower canine, when the mandible is viewed laterally (in C. salvini and C. villosum , the coronoid process is at the same level as the canines). The p2 crown is ½ to ⅔ the height of p4, and is ap- proximately as high as long (longer than tall in C. salvini , C. scopaeum , C. improvisum , and C. villosum ) ( Fig. 20 ). The p2 does not touch p4. The mandible with a small p2 identified by Oprea & Wilson (2008) as C. doriae (their Figure 2 ) is a C. villosum (USNM 309905).

The only other species of Chiroderma sympatric with C. doriae is C. villosum , from which doriae can be differentiated by its larger size, the both pairs of facial stripes wide and conspicuous (narrow and inconspicuous in villosum ), bicolor noseleaf, and ears with pale margins. C. doriae also lacks posterior palatine processes, has converging I1s (usually parallel in villosum ), p2 taller than longer (p2 longer than tall in villosum ), relatively short c (tall in villosum ), and lacks a frontal gap when cranium and mandible are in occlusion ( Fig. 14 ).

Geographic Variation and Phylogeography. The phylogenetic analyses of 16 sequences of C. doriae did not show geographic structuring, with haplotypes from geographically distant regions, e.g. from Paraguay north to Rio Grande do Norte, Brazil grouped together ( Fig. 21 ). Although intraspecific genetic variation (0.49%) is considered low ( Table 3), the phenotype of C. doriae varies geographically. Specimens from the Caatinga of Piauí and Ceará, and from the Amazonia—Cerrado ecotone in Maranhão, are significantly smaller and have much paler pelage than specimens from the Mata Atlântica and Cerrado, which are larger and have the pelage color varying from pale brown to dark brown ( Figs. 18 , 20 ).

Given that population samples of C. doriae from the Caatinga (Ceará and Piauí) and Maranhão are phenotypically distinct from those from Mata Atlântica and Cerrado, but do not compose a distinct haplogroup, we treat this population as a subspecies for which the available name is vizottoi , described by Taddei & Lim (2010). Subspecific recognition followed Patten (2015) for phenotypically distinct and geographically restricted groups that do not form clades.

Furthermore, geographic variation in C. doriae appears to be correlated with temperature and rainfall ( Fig. 22 , Tables 11 and 12). Precipitation in driest month (variable BIO14 of WorldClim), precipitation in driest quarter (BIO17), precipitation in warmest quarter (BIO18), temperature seasonality (BIO4), and latitude were the variables having the strongest correlation with size. This suggests that individuals are larger in regions having a more seasonal climate, or at higher latitudes, and in areas with greater rainfall (Appendix 5).

Subspecies. We recognize two subspecies in Chiroderma doriae .

Figures

FIGURE 2. Adult female Chiroderma villosum captured in Puerto Maldonado, Madre de Dios, Perú, in August 2016 (ROM F63087). Note the faint facial stripes, the long guard hairs on the head, and the noseleaf with notched tip.

FIGURE 9. Lateral view of skull and mandible in occlusion for A) Chiroderma salvini (ROM 99703), B) Chiroderma scopaeum (TTU 110649), C) Chiroderma d. doriae (TTU 99569), D) Chiroderma villosum (USNM 560607), and E) Chiroderma improvisum (ROM 126002).

FIGURE 14. Frontal view of skull and mandible in occlusion for A) Chiroderma salvini (ROM 99703), B) Chiroderma scopaeum (TTU 110649), C) Chiroderma d. doriae (TTU 99569), D) Chiroderma villosum (USNM 560607), E) Chiroderma improvisum (ROM 126002).

FIGURE 18. Dorsal view of the skin of A) Chiroderma doriae doriae (ALP 6121—Brazil, Rio de Janeiro) and B) C. d. vizottoi (ALP 10421—Brazil, Ceará).

FIGURE 19. Dorsal (A) and ventral (C) views of the skull of Chiroderma doriae doriae (TTU 99569—Paraguay, La Cordillera), and dorsal (B) and ventral (D) views of the skull of C. doriae vizottoi (ALP 10421—Brazil, Ceará).

FIGURE 20. Skull and mandible, in lateral view, of A) Chiroderma doriae doriae (TTU 99569—Paraguay, La Cordillera); B) C. doriae vizottoi (ALP 10421—Brazil, Ceará).

FIGURE 21. Phylogenetic relationships of Chiroderma doriae, C. gorgasi and C. trinitatum, based on 87 sequences of the cytochrome c oxidase subunit 1 gene. Localities in parentheses are detailed in the gazetteer (Appendix 1). This subtree is a detailed version of the clades named “doriae”, “gorgasi”, “trinitatum A”, and “trinitatum B” in figure 4.

FIGURE 22. Dispersion of the two first principal components (PC1) of 20 climatic variables, and 13 morphometric variables of Chiroderma doriae. Pearson correlation coefficient = -0.744.