Cordylus angolensis (Bocage, 1895)

Bates, Michael F., Lobon-Rovira, Javier, Stanley, Edward L., Branch, William R. & Vaz Pinto, Pedro, 2023, A new species of green-eyed Cordylus Laurenti, 1768 from the west-central highlands of Angola, and the rediscovery of Cordylus angolensis (Bocage, 1895) (Squamata: Cordylidae), Vertebrate Zoology 73, pp. 599-646 : 599

Cordylus angolensis (Bocage, 1895)

Figs 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11

Chresonymy.

Zonurus angolensis Bocage, 1895: 25. Type locality. Caconda, Angola.

Cordylus cordylus angolensis - Loveridge (1944a: 38); Mertens (1955: 59, 1971: 53).

Cordylus angolensis - Visser (1971: 19); Broadley and Branch (2002) partim; Branch et al. (2005) partim; Adolphs (2006: 17); Broadley (1971: 22); Broadley (2006: 1) partim; Stanley et al. (2011: 67) partim; Greenbaum et al. (2012: 32) partim: Caconda; Reissig (2014: 33) partim.

Bocage’s (1895) description of a single type specimen (MBL 429, adult male) of C. angolensis was fairly terse and he did not provide any illustrations. He described the dorsal parts of the head and back as being a variety of brown and black on a pale tan, with two longitudinal series of small irregular whitish spots along the back, the tail brown, with venter white. Regarding scalation he noted only that: Internasal (= frontonasal) rhomboid, in contact with the anterior part of the frontal, thus separating the prefrontals; loreal absent; preocular large and in contact with the posterior part of the nasal; nasal large, slightly domed, pierced halfway up the posterior edge; gular with quadrangular scales, smooth, narrow, juxtaposed, of various shapes, and significantly smaller than in C. cordylus ; dorsals in 26 longitudinal and 24 transverse rows; ventrals in 16 longitudinal and 27 transverse rows; two large pre-anal scales separated on the median line by two small plates; pre-anal pores 6 [presumably number of femoral pores on each thigh]; snout-vent length = 74 mm; tail length = 78 mm (incomplete). Head width/SVL = 24.3%; head length/SVL = 31.1% [based on head and body measurements provided].

In 1968 Dr Donald G. Broadley (in litt., 18 January 2012) examined the holotype (MBL 429) of C. angolensis at the Museu Bocage in Lisbon and recorded the following data: nasals in broad contact, loreal absent (fused with preocular); frontal and frontonasal in contact, suboculars 3, supraciliaries 3, gulars 26, dorsals in 24 transverse and 26 longitudinal rows, ventrals in 27 transverse and 16 longitudinal rows, femoral pores 6 on each thigh; outer three rows of ventrals keeled and mucronate; SVL = 78 mm; tail length 74 mm tail (broken). As mentioned earlier, Broadley (1971: 22) noted that the tail of the holotype was "almost equal to snout-vent length in spite of the tip being missing".

According to Madruga (2011: 4), despite the fire at Museu Bocage in 1978, "many of Bocage’s papers, folder, manuscripts and correspondence still exist today". From February to April 2012 MFB corresponded with Catarina Madruga (Museu Bocage) who searched through Bocage’s correspondence and notes in the hope of finding information and/or diagrams of the holotype of C. angolensis , but nothing was found. The holotype of C. angolensis is no longer available, so in order to stabilise the taxonomy we designate a neotype that is in agreement with Bocage’s (1895) description of the species (see above).

The new specimens from Taqueta Mountain were collected about 100 km west of Caconda and are assigned to C. angolensis on the basis of their similarity to the holotype as described by Bocage (1895) and Broadley (pers. comm.) (see details above). Their colour patterns are similar, as are several of the scale counts. Bocage (1895) noted that the frontonasal was in contact with the frontal in the holotype; and while this was the case in only two of the five new specimens, this is clearly a variable character. Bocage's (1895) holotype of C. angolensis reportedly had 16 longitudinal rows of ventrals, whereas the Taqueta Mountain specimens examined here all had 14 rows. Such discrepancies probably reflect the likelihood that different observers count these rows differently, e.g., some observers may exclude a poorly differentiated lateral row that others count. A similar problem may occur with regards to the longitudinal rows of dorsals (26 in holotype versus 20-23 in new material), transverse rows of ventrals (27 versus 22-24) and gulars across the throat (26 versus 20-21).

Neotype.

The holotype (MBL 429) is no longer in existence, and therefore we propose and describe one of the new specimens as neotype: MNCN 50648, an adult male from Taqueta Mountain, Benguela Province, Angola (-13.7778°, 14.1794°; 2112 m a.s.l.) collected 10 August 2017 by Afonso Vaz Pinto and Pedro Vaz Pinto.

Additional new material.

Adult males: MNCN 50649, CHL 611, CHL 613; adult female: CHL 615. Same collecting information as neotype.

Diagnosis.

A medium to large rupicolous Cordylus with a moderately depressed head and body. Referred to Cordylus (rather than any other species of Cordylidae ) by the following combination of characters: head distinct from body, two pairs of large and well developed limbs (body serpentiform, head indistinct from body, and limbs rudimentary in Chamaesaura Schneider, 1799), scales on back large and keeled (granular in Platysaurus Smith, 1844, partly granular in Pseudocordylus Smith, 1838 and Hemicordylus Smith, 1838), non-spinose occipitals (spinose in Smaug Stanley et al., 2011), 23-24 transverse dorsal scale rows (40-43 in Ninurta Stanley et al., 2011; 31-46 in Karusasaurus Stanley et al., 2011; 15-16 in Ouroborus Stanley et al., 2011); loreal absent (present in Smaug , Ninurta , Ouroborus , Karusasaurus , and Namazonurus Stanley et al., 2011).

Cordylus angolensis is distinguishable from other members of its genus by the following combination of characters: (1) back dark brown with a paravertebral series of pale markings; (2) top of head plain brown or with occasional pale blotches; (3) iris of the eye brown; (4) scales of the first transverse row of dorsals similar in appearance to those of the row behind; (5) loreal shield absent; (6) nostril pierced in the posterior part of a large nasal, situated behind the suture of rostral and first supralabial, usually well separated from both the first supralabial and the preocular; (7) a regular row of six enlarged, non-spinose occipitals; (8) Frontonasal separated from the frontal by a pair of prefrontals (each of which usually exceeds it in size) or in contact; (9) Anterior pair of parietals usually in contact anteriorly; (10) dorsolateral and lateral scales may be weakly to moderately spinose; (11) tail spinose, but more weakly so distally; (12) dorsal scale rows transversely 24-25; (13) dorsal scale rows longitudinally 20-23; (14) ventral scale rows transversely 22-24; (15) ventral scale rows longitudinally 14; (16) subdigital lamellae on 4th toe 14; (17) femoral pores per thigh 5-6 in males and females; (18) differentiated femoral scales [generation glands] per thigh in males 19-25; (19) premaxillary teeth 7.

Its status as a distinct species is supported by monophyly with high levels of support from a suite of three mitochondrial and six nuclear markers (see above); and it differs from C. ‘Mombolo’ (see below), the most similar species genetically and morphologically, by an uncorrelated ND2 p-distance of 9.22% (Table 3 ).

Comparisons with other Cordylus species.

It differs from most other Cordylus (except C. ukingensis [Loveridge, 1932], C. macropholis [Boulenger, 1910], and C. vittifer [which occasionally has a loreal]) in lacking a loreal. It differs from C. ukingensis and C. macropholis by virtue of its smooth (rarely with a few weak keels on a few scales) versus strongly keeled (even spinose in C. macropholis ) gulars, as well as by having its nostril pierced near the middle of the posterior part of the nasal scale (versus infero-posteriorly). Differs from C. tropidosternum by having smooth versus keeled gulars, and having the nostril well separated from the first supralabial (not in contact or near-contact); from C. rhodesianus by having distinctly rugose versus finely rugous to smooth upper head shields, 24-25 versus 25-29 transverse rows of dorsals, and a straight versus curved sulcus dividing the posterior part of the nasal; from C. jonesii by having its nostril pierced halfway up the posterior edge of the nasal rather than towards the centre, and a straight versus curved sulcus dividing the posterior part of the nasal; and from C. marunguensis which has the nostril pierced centrally on the lower margin of the nasal. Distinguished from C. vittifer and C. machadoi , C. namakuiyus and C. phonolithos by always lacking a loreal scale, having most or all scales of the first transverse row of dorsals of similar length (rather than longer) than those of the next row, and by having a pair of paravertebral rows of pale greenish-cream spots or blotches versus a lack of these. Most similar to C. ‘Mombolo’ (see below).

Description of the neotype.

MNCN 50648 (Figs 4 - 6 , 8 - 11 ; Tables 5 , 6 ). External morphology: Head and body moderately depressed. SVL 88.4 mm. Tail 62.8 mm (tip missing), 0.71+ times as long as SVL. Head 24.6 mm, 1.18 times as long as wide (20.9 mm); head depth 10.6 mm, 50.6% head width. Upper head shields coarsely rugose. Nasals in broad contact; frontonasal quadrangular and slightly smaller than a prefrontal; prefrontals in contact with one another (separating frontonasal from frontal), and each one in contact with the frontal, first supraocular, preocular and a large nasal on either side; frontal in contact with first and second supraoculars, followed by a pair of frontoparietals in median contact; interparietal flask-shaped, narrowing and extending anteriorly to completely separate the anterior parietals; each anterior parietal smaller than a posterior parietal; a straight row of six rugose but non-spinose occipitals. Four supraoculars and three supraciliaries. Nasals large, with nostril pierced more-or-less centrally in the posterior part of the scale; nostril separated from preocular by a distance of more than half its diameter, distinctly separated from first supralabial by a distance almost equal to the height of the latter scale (and almost equal to the greatest extent of the nostril); nasal divided posteriorly at the level of the middle of the nostril. Loreal absent. Lower eyelid with 9-10 vertical septa. Three suboculars, well separated from the lip, with another large scale bordering the eye between posterior subocular and postocular. Rostral semi-divided dorsally and about twice as broad as deep; supralabials 6; infralabials 6; sublabials 5. Mental almost twice as broad as long. Gulars vary considerably in size and shape, from rectangular (especially on the sides) to square and oval, mostly smooth (a few centrally have feeble blunt keels medially) and at most subimbricate, forming about 12 transverse rows (from first row in line with angle of jaws to last distinct row posterior to chin shields), and 20 longitudinal rows between posterior angles of jaws; 5 chin shields (including tiny median scale anteriorly) in contact with 1st pair of sublabials; two pairs of distinctly enlarged chin shields posterior to these.

Dorsal scales rectangular, rugose, moderately keeled (less so medially), seldom spinose or mucronate, not serrated at the posterior edges; laterals oval, juxtaposed, rugous, sharply keeled and moderately spinose, no additional spines on the free end of scales; dorsals plus laterals in 25 transverse rows and 20 longitudinal rows (vertebral scales slightly smaller); on the central part of the belly the mesial ventrals are rectangular (transversely) and larger than others, the next row on either side with slightly rectangular scales, including the next two rows on either side; ventrals mostly smooth, but 2-3 lateral rows on either side with some obtusely keeled scales; ventrals in 22 transverse and 14 longitudinal rows (plus a row of oval, keeled scales on either side); a pair of enlarged and somewhat oval pre-cloacal plates is followed anteriorly (before the ventrals) by two transverse rows of much smaller irregular scales.

Scales on limbs above are large, strongly keeled and spinose; scales under fourth (longest) toe 14 on left and right feet; femoral pores 6 on left thigh, 5 on right, with distinct plugs of yellowish secretion; differentiated glandular femoral scales on thigh 21 on left, 20 on right. Tail with whorls of large, elongate, strongly keeled, spinose (spines directed backwards and longest superolaterally), weakly serrated, scales; supracaudals strongly keeled throughout most of their length, subcaudals basally distinctly keeled mainly on the distal half. Scales on palms of hands and soles of feet moderately to obtusely keeled; supradigital scales of hands smooth to weakly keeled, of feet smooth to moderately keeled; subdigital scales of hands weakly keeled, of feet moderately keeled.

Colour: The colour pattern of the neotype in life is similar to that described for the holotype (see above). The back is a mixture of light and dark brown, with some of the darker markings forming ill-defined transverse bands, and there is a series of greenish-cream blotches, mostly elongated, arranged in close proximity paravertebrally (about eight pairs). Top of the head is a mixture of pale and dark brown, with an ill-defined pale median band longitudinally. The upper parts of the tail are brown, with some keels dark brown. Belly is dirty white and the throat cream. Bocage (1895) recorded the markings on the back as ‘whitish’, but this may have been in reference to preserved material that had faded somewhat.

Cranial skeleton (Fig. 8 , Table S1): Segmented mesh file of MNCN 50648 can be found here http://tinyurl.com/CordylusAngola. Morphosource link to tomogram stacks doi.org/10.17602/M2/M529985. The scales of the dorsal and temporal regions of the skull and the ventrolateral aspects of the jaws are underlain with rugose osteoderms. These osteoderms fuse to the parietal, frontal and postorbital bones, although the mesokinetic and metakinetic joints appear unobstructed and flexible. Lateral maxilla and anterior aspect of the premaxilla lack osteoderms. The parietal is pentagonal, with five osteoderms that underlie the parietal shields fused to its dorsal surface, and a narrow, bifid, ‘Y’ -shaped medioposterior process that articulates with the sagittal crest of the supraoccipital. Three large osteoderms are fused to the frontal, which is unpaired and clasped by the parietal at its posterolateral edge. The upper temporal fenestra is obscured anteriorly by a large osteoderm fused to the dorsal surface of the postorbital bone, and posteriorly by two unfused rectagonal osteoderms that overlie the squamosal. Premaxilla is unpaired and contains seven pleurodont teeth, with a dorsal process that extends posteriorly to intersect the nasals, which themselves overlie the frontal. The maxillae are typically scinciform, with a deeply grooved crista dentalis, a deep fossa that lodges the lacrimal sac, 9 (left) or 11 (right) lateral foramina, and 22 (left) or 23 (right) teeth. Teeth display pleurodont attachment and are unicuspid, with a slight concave surface where they connect with the mandibular teeth. No palpebral is present but the prefrontals possess a small protuberance, forming a shelf that directly underlies the anteriormost superorbital osteoderm. The jugal is triangular in cross-section and asymmetrically T-shaped, with a tapering anterior process and a broad, truncated posterior process that extends along and past the posterior edge of the maxilla. The lacrimal bone is small, flattened and oval, slightly bicuspid anteriorly, the two processes meeting prefrontal cusps to bracket the lacrimal duct. Pterygoids are edentate and extend back to connect with the quadrates, becoming C-shaped in cross-section posterior to the epipterygoid condyle. The squamosal is curved and blade-like, circular in cross-section anteriorly, becoming flattened posteriorly, where it articulates with the cephalic condyle of the quadrate and the supratemporals. Supratemporals are flattened, ovoid and not fused with the elongate paraoccipital processes. The posterior aspect of the prootic not fully fused with the otooccipital, resulting in a deep groove along the dorsal aspect of the paraoccipital processes. Quadrates very broad with a pronounced ridge and concave region at the lateral edge of the adductor musculus mandibulae posterior origin. The supraoccipital has a strong sagittal crest that extends posteriorly to contact the ventral surface of the medioposterior process of the parietal. The prootic bears an extended alar process and a well-developed, rhomboid christa prootica, and a very weak supratrigeminal process. Basipterygoid processes are well developed and flattened. The lower jaw possesses a large adductor fossa, a highly flattened and medially extended retroarticular process, a medially open Meckelian canal that is closed posteriorly by a large splenial, and a dentary with a strong subdental shelf; 25 (left) and 27 (right) mandibular teeth, and six dentary foramina.

Postcranial skeleton : Segmented mesh file of MNCN 50648 can be found here (tinyurl.com/Cang1Skel Morphosource link to tomogram stack https://doi.org/10.17602/M2/M529986). The axial Cordylus skeleton comprises 26 presacral (eight cervical, three sternal, two xiphisternal, five long asternal ribs with ossified costal cartilage, seven short asternal ribs and one very short pair of ribs immediately anterior to the sacral vertebrae), two sacral and 15 (incomplete, regenerated tail) caudal vertebrae. Cervical ribs 4-6 are distally flattened and biphid, with the ventral processes more elongated. Pubis flattened and curved with a large, ventrally angled pectineal tubercle. Pubic symphysis flattened and triangular, separating the pubes entirely. Hyperischiam and hypoischium well developed. Sternal plate broad with no fontanelle. Interclavicle cruciform. Digits three and four on right manus are truncated, but display a typical phalangeal pattern of 2-3-4-5-3 for the manus and 2-3-4-5-4 for the pes.

Osteoderms : (Fig. 9 ) The dorsal trunk is covered in rectangular, dorsomedially keeled, imbricate osteoderms, each roughly three times as long as wide. Dorsal osteoderms are arranged in whorls and become progressively more oval and better separated laterally. The nuchal osteoderms are spined posterior to the tympanic opening. Ventral osteoderms are delicate and plate-like, and concentrated in the gular, antero-pectoral and abdominal regions. No precloacal osteoderms. The forelimbs are covered in keeled, imbricate, rhomboid osteoderms, except for the axillary, antecubical and palmar regions, which are unarmoured. The hindlimbs are covered in rhomboid osteoderms, except for the ventral femoral, popliteal and plantar regions. Hindlimb osteoderms are unkeeled on the anterior thigh, and become more spinose posteriorly and distally. The caudal osteoderms are large, robust and arranged in imbricated whorls, feebly keeled and mucronate along the dorsal and ventral aspects, becoming more heavily spined laterally.

Variation in additional new material.

(Figs 4 - 6 ; Tables 5 , 6 ). External morphology: Detailed morphometrics and mensural data for the new material is presented in Tables 5 - 6 . All additional material agrees in general with the holotype and neotype, but differs as follows: Less than half the length of the nasals are separated by the frontonasal in CHL 613; frontonasal pentagonal in MNCN 50649; size of the frontonasal varies from much smaller than a prefrontal scale (CHL 613), only slightly smaller (CHL 611), about equal to or only slightly larger (CHL 615) or distinctly larger (MNCN 50649); frontonasal and frontal in narrow (CHL 611) and broad (MNCN 50649) contact, separating frontonasal and frontal. Shape and size of the interparietal varies: usually kite-shaped (with most acute angle anteriorly) and separating more than three-quarters of the anterior parietals, but rhomboidal (diamond-shaped) and separating only about half the anterior parietals in CHL 615. Occipitals only 7 in MNCN 50649. Nostril pierced in the middle (not posterior part) of the nasal in CHL 611; nostril separated from pre-ocular by a distance varying from less than half its diameter (right side in CHL 613) to about equal thereto (e.g., left side of CHL 613); and nostril separated from first supralabial by more than half the height of the latter and a distance about equal to the first supralabial on the left side in CHL 611 and CHL 613. Supralabials 5 on right side of head in CHL 611. In CHL 613 a small, discrete, triangular scale ( ‘postnasal’) is present between the nasal, preocular and first two supralabials on the right side of the head. Rostral undivided, and partly fragmented in MNCN 50649. Mental less than twice as broad as long in CHL 611. Gulars smooth, juxtaposed to subimbricate. Six chin shields (including tiny median one) in contact with first supralabials in CHL 611. Dorsals in 24-25 rows transversely, and 20-23 rows longitudinally. Ventrals in 22-24 rows transversely. Femoral pores 6 on left and right limbs in CHL 613; differentiated glandular femoral scales in males 19-25 per thigh, but absent in female CHL 615.

Colour: Similar to that described for the neotype, but CHL 611 and CHL 615 have a few scattered cream markings on the top of the head, and none have a pale median band.

Size: Largest male (CHL 611, Taqueta Mountain): SVL 88.5 mm, tail length 73.6 mm (original), total length 162.1 mm, head length (HL) 23.2 mm, head width (HW) 22.1 mm, head height (HH) 10.9 mm. Largest female (CHL 615, Taqueta Mountain): SVL 103.1 mm, tail length 84.1 mm (original), total length 187.2 mm, HL 25.7 mm, HW 22.3 mm, HH 10.3 mm.

Habitat.

Although no specific habitat information was available in Bocage’s (1895) original description, the morphology of this species suggested that it is rupicolous, as are most other congeners ( Branch 1998). The type locality of Caconda, where José de Anchieta was based, lies in relatively flat terrain between 1500 and 1700 m a.s.l. The local habitat there today comprises mostly agricultural fields, interspersed with very occasional, scattered, small granite outcrops. In the past, the region of Caconda was probably covered by well-developed miombo woodlands, characterised by dominance of tree species such as Julbernardia paniculata , Brachystegia spiciformis and Brachystegia spp. ( Barbosa 1970). Nevertheless, the species has never again been found in the vicinity of Caconda, but was instead found almost 100 km to the west on Taqueta Mountain, at 2112 m a.s.l., where the habitat is typical of the Angolan highlands (Fig. 11B ). All specimens were found in cracks and crevices in granite outcrops present on moderate to steep slopes, surrounded by well-developed montane grassland in proximity to Afromontane forest patches in deep ravines.

Distribution.

Although the original type locality is giv-en as Caconda ( Huíla Province), efforts over more than one century to rediscover the species at or near that locality have failed. The fact that Anchieta was based at Caconda for more than 20 years ( Banha de Andrade 1985), and the holotype -appears to be the only specimen collected, suggests that the species was likely rare there in those days possibly due to scarcity of rocky habitat, which subsequently must have been further impacted by human encroachment and use of rocks for construction. -Alternatively, the holotype may have also been collected on the mountains criss-crossed by the 19th century land routes linking Caconda to the major coastal city of Benguela, a route that was often followed by Anchieta himself and his assistants. While conducting surveys in this region in 2017, and specifically targeting the mountains thought to have been along those historical routes, we made the discovery of a population of C. angolensis at Taqueta Mountain. This new locality is currently the only site where this species is known to occur with any certainty (Fig. 12 ). Nevertheless, it is likely to be present on various rocky hills on the highlands west of Caluquembe, along the ridge of the southern Angolan escarpment, where suitable habitat is present.

Localities.

Angola: Ca-con-da (-13.7199°, 15.0648°), Ta-que-ta Mountain (-13.7778°, 14.1794°).

Conservation.

This species is known from only one locality, and little is known about its biology or population trends. Nevertheless, it should be noted that montane habitats in Angolan highlands are currently under anthropogenic pressure due to widespread excessive burning, cut-ting of remnant forests, and overgrazing of grasslands, all of which may negatively affect the species. The actual range of this species is difficult to infer and threats cannot be fully assessed at this time, but a Data Deficient categorisation, based on IUCN (2022a) Standards and Petitions Committee criteria, may apply.

Remarks.

It was not possible to locate the specimen of ' Zonurus cordylus ' from Aruwimi (presumably Aruwimi River, a tributary of the Congo River) in northern Democratic Republic of the Congo as documented by Boulenger (1897). However, we reject Loveridge’s (1944a) inclusion of this record under C. c. angolensis . If the locality is indeed valid and a population of Cordylus does/did occur in the vicinity of this river, it is likely - as suggested by Loveridge (1944a) - to represent an undescribed species. The Aruwimi River enters the Congo River at Basoko and extends eastward to a position north of Bunia (near Nizi) where it continues, as the Nizi River, to the vicinity of Jiba near the western shores of Lake Albert. The nearest other cordylids are C. tropidosternum (see map in Greenbaun et al. 2012) from northern Tanzania, about 700 km south-east from the nearest part of the Aruwimi/Nizi River, and Katanga Province (D.R. C. ) about 900 km to the south.

Figures

Figure 4. Dorsal views of the head in Angolan Cordylus. Cordylus angolensis - A CHL 611, B CHL 615, C MNCN 50649, D CHL 613, E MNCN 50648 (neotype); C. momboloensis sp. nov. - F MNCN 50760 (paratype), G FKH 0125 (paratype), H FKH 0127 (paratype), I FKH 0128 (paratype), J FKH 0129, K PEM R 25217 (holotype), L MNCN 50761 (allotype); C. namakuiyus - M PEM R 25218, N CHL 616, O CHL 609; C. phonolithos - P CHL 852, Q CHL 1056, R MNCN 50651, S CHL 851, T CHL 1057, U MNCN 50652, V CHL 848; and C. machadoi - W CHL 701, X CHL 700, Y PEM R 19784. Photos: Pedro Vaz Pinto (A-N, P-V), Timoteo Julio (O, W-X), and William R. Branch (Y).

Figure 5. Lateral views of the head in Angolan Cordylus. Cordylus angolensis - A CHL 611, B CHL 615, C MNCN 50649, D CHL 613, E MNCN 50648 (neotype); C. momboloensis sp. nov. - F MNCN 50760 (paratype), G FKH 0125 (paratype), H FKH 0127 (paratype), I FKH 0128 (paratype), J FKH 0129, K PEM R 25217 (holotype), L MNCN 50761 (allotype); C. namakuiyus - M PEM R 25218, N CHL 616, O CHL 609; C. phonolithos - P CHL 852, Q CHL 1056, R MNCN 50651, S CHL 851, T CHL 1057, U MNCN 50652, V CHL 848; and C. machadoi - W CHL 701, X CHL 700, Y PEM R 19784. Photos: Pedro Vaz Pinto (A-N, P-V), Timoteo Julio (O, W-X), and William R. Branch (Y).

Figure 6. Ventral views of the head in Angolan Cordylus. Cordylus angolensis - A CHL 611, B CHL 615, C MNCN 50649, D CHL 613, E MNCN 50648 (neotype); C. momboloensis sp. nov. - F MNCN 50760 (paratype), G FKH 0125 (paratype), H FKH 0127 (paratype), I FKH 0128 (paratype), J FKH 0129, K PEM R 25217 (holotype), L MNCN 50761 (allotype); C. namakuiyus - M PEM R 25218, N CHL 616, O CHL 609; C. phonolithos - P CHL 852, Q CHL 1056, R MNCN 50651, S CHL 851, T CHL 1057, U MNCN 50652, V CHL 848; and C. machadoi - W CHL 701, X CHL 700, Y PEM R 19784. Photos: Pedro Vaz Pinto (A-N, P-V), Timoteo Julio (O, W-X), and William R. Branch (Y).

Figure 7. Arrangement of the nasal shield, nostril and scales of the snout in Cordylus: A C. angolensis (CHL 615 - Taqueta Mountain, Angola); B C. momboloensis sp. nov. (AMNH R 47333 - ' Mombolo', Angola); C C. machadoi (TM 40133 - 1.4 km NE of Humbia, Angola); D C. namakuiyus (PEM R 25218 - 10.4 km S of Rio Mucungo on tar road to Bentiaba, Namibe Province, Angola); E C. phonolithos (CAS 263581, holotype - vicinity of N'Dolondolo, Serra da Neve, Angola); F C. vittifer (NMB R 8721 - Farm Goede Hoop 182, Mpumalanga Province, South Africa); G C. tropidosternum (PEM R 13288 - Moebase village, Zambesiaca Province, Mozambique); H C. jonesii (NMB R 8656 - Farm Doorenwaard 313, Limpopo Province, South Africa); I C. rhodesianus (NMB R 10034 - York Forest Land, Zimbabwe); J C. cordylus (NMB R 9525 - De Hoop Nature Reserve, Western Cape Province, South Africa). Photos: Javier Lobon-Rovira (A), Michael F. Bates (B, C, F, H, I, J), William R. Branch (D, G), and Luis M. P. Ceriaco (E).

Figure 8. Computed tomography images depicting the cranial osteology of the five species of Cordylus from Angola.

Figure 9. Computed tomography generated images showing the osteology of the five Angolan Cordylus species. Osteoderms are highlighted in blue-green.

Figure 10. Neotype (MNCN 50648) of Cordylus angolensis from Taqueta Mountain, Benguela Province, Angola. A dorsal aspect, B ventral region, C top of the head, D left side of the head, E ventral side of the head. Photos: Pedro Vaz Pinto.

Figure 11. Cordylus angolensis: live neotype (A) and habitat at the collecting site of Taqueta Mountain, Angola (B); and C. momboloensis sp. nov.: live holotype (C) and habitat at the type locality of Sandula, Angola (D). Photos: Pedro Vaz Pinto (A, B), and William R. Branch (C, D).

Figure 12. Geographical distribution of Cordylus angolensis (dark blue) and C. momboloensis sp. nov. (green) in Angola. The distribution of the three species of the C. machadoi group (C. machadoi [red], C. namakuiyus [pale blue], C. phonolithos [yellow]) is also indicated. Type localities are indicated by stars; for C. angolensis, the original type locality of Caconda is indicated by a black star, while the neotype locality is indicated by a dark blue star. Locality records are from the present study (see species accounts and Appendix 1) as well as Bocage (1895), Laurent (1964), Stanley et al. (2016), Marques et al. (2019), and Lobon-Rovira et al. (2022 b).