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Colombophis portai Hoffstetter & Rage, 1977 (Figs 3-5) Colombophis portai Hoffstetter & Rage, 1977: 174. REVISED DIAGNOSIS. — Fossil snake with pre-cloacal vertebrae medium to large in size (cl = c. 5-11 mm); the neural arch is depressed, with a shallow median notch in the posterior border; neural spine is reduced to a small tubercle with a circular or triangular outline from dorsal view, and is restricted to the posterior end of the neural arch; prezygapophyses are anterolaterally oriented and highly inclined above the horizontal plane, reaching the level of the zygosphene roof; prezygapophyzeal process is short; presence of paracotylar and parazygantral foramina is variable; synapophyses are undivided; haemal keel is broad with a single or divergent apophysis in the posterior end; subcentral foramina are usually placed close to the sagittal plane, usually small but can be enlarged or absent; the centrum length is longer than the neural arch width (cl> naw); the neural arch is longer than width (pr-po> naw) and the length is proportional to its high (pr-po = c. h). REFERRED MATERIAL. — VPPLT-0067, an anterior-trunk vertebra (Fig. 3C); VPPLT-0068 (Fig. 3D), an anterior-trunk vertebra; VPPLT-0070, a posterior-trunk vertebra; VPPLT-0430, a mid-trunk vertebra; VPPLT-0799, a mid-trunk vertebra; VPPLT-0845, a fragmentary mid-trunk vertebra; VPPLT-0869, a posterior-trunk vertebra; VPPLT-0871, a fragmentary mid-trunk vertebra; VPPLT-1006, a mid-trunk vertebra (Fig. 3A, B); VPPLT-1160, a fragmentary posterior-trunk vertebra; VPPLT-1166, a posterior-trunk vertebra; VPPLT-1253, a posterior-trunk vertebra; VPPLT-1551, two associated mid-trunk vertebrae; VPPLT-1564, nine pre-cloacal articulated vertebrae together with seven associated and badly preserved fragments of rock matrix with ribs and vertebral fragments embedded (Fig. 5); VPPLT-1731, a fragmentary mid-trunk vertebra; VPPLT-1734, a mid-trunk vertebra; VPPLT-1735, four mid-trunk vertebrae fragments associated with a posterior-trunk vertebra (Fig. 3F); VPPLT-1738, a mid-trunk vertebra; VPPLT-1739, an anterior-trunk vertebra (Fig. 3E); VPPLT-1740, five mid-trunk vertebrae fragments associated with a posterior-trunk vertebrae and a post-cloacal vertebrae (Fig. 4)., Published as part of Alfonso-Rojas, Andrés, Vanegas, Rubén D., Mariño-Morejón, Elizabeth & Cadena, Edwin-Alberto, 2023, Newly discovered fossils provide novel insights on the biology of the South American Miocene snake Colombophis Hoffstetter & Rage, 1977, pp. 377-399 in Geodiversitas 45 (13) on page 382, DOI: 10.5252/geodiversitas2023v45a13, http://zenodo.org/record/8157175, {"references":["HOFFSTETTER R. & RAGE J. C. 1977. - Le gisement de vertebres miocenes de la Venta (Colombie) et sa faune de serpents. Annales de Paleontologie (Vertebres) 63 (2): 161 - 190."]}

Colombophis sp. REFERRED MATERIAL. — More than 20 vertebral fragments (see Appendix 3), most of them correspond to partially complete or fragmentary precloacal vertebrae. REMARKS Listed specimens were assigned to Colombophis as they exhibit the following features: medium to large size (cl = c. 8 mm, po-po = c. 11 mm); slightly depressed neural arch with a shallow median notch on the posterior border; the neural spine is reduced and restricted to the posterior end of the neural arch; moderately inclined prezygapophyses which usually reach the zygosphene roof level; short prezygapophyseal process; paracotilar foramina present in most vertebrae; weakly divided synapophyses; broad haemal keel with small to absent subcentral foramina close to the sagittal plane and bear one or two small apophyses with a tubercular shape placed on the ventral margin on anteriorly to the condyle. Lateral foramina located near the base of the neural canal anteriorly to the neural arch constriction. DESCRIPTIONS Anterior-trunk vertebrae These vertebrae are shorter (cl Colombophis spp. (C. portai, C. spinosus, and C. sp.). Despite being broken on most of the specimens, the hypapophyses are postero-ventrally oriented and located behind the sub-central foramina also, hypapophyses have a circular (Fig. 3D) or a flattened shovel-like shape (Figs 3E; 6E) in posterior view. Mid-trunk vertebrae These vertebrae are the largest and most distinctive of Colombophis spp. Prezygapophyses are anterolaterally oriented, and usually reach the zygosphene roof level. Ventrally, the haemal keel is broad, usually with a pair of small sub-central foramina placed anterior to the coronal plane (Figs 3A, B; 4A, B; 5I, J; 6 A-C). The posterior end of the haemal keel usually presents a tubercular or bifid structure. Neural arch is broad and slightly depressed, visible from posterior region view. The zygantra possesses a deep foramen inside. Neural spines are restricted to the posterior region of the neural arch, being poorly developed (tubercle like) in C. portai (Figs 3A, B; 4 A-D; 5G, H), but well developed in C. spinosus where the anterior edge of this structure rarely reach the coronal plane of the vertebra (Fig. 6 A-D). Posterior-trunk vertebrae These vertebrae are easily recognized by the presence of subcentral paramedian lymphatic fossae, which create a notched A1 A2 A3 A4 A5 section between the cotyle and the synapophyses (Figs 3F; 4E, F; 6F). Pre-condylar constriction of the centrum is strong compared to anterior or mid-trunk vertebrae, which also makes the haemal keel less broad. Prezigapophyses are less inclined and do not reach the zygosphene level. In some specimens of C. portai, the posterior end of the haemal keel extends ventrally creating a structure similar to a hypapophysis (Fig. 4E,F) Ribs Ribs are only present in VPPLT-1564 specimen, unfortunately they are badly preserved. However, they seem to be fully ossified and slender, apparently longer than the vertebral centrum (Fig. 5C, D). The articular facet is smooth without a clear division on the articular facets, which corresponds to undivided synapophyses. A1 A2 A3 A4 A5 Post-cloacal vertebrae A potential post-cloacal vertebra was found associated in the C. portai specimen VPPLT-1740.(Fig.7A) This vertebra is considerably more vaulted than the associated precloacal vertebrae(Fig.4). Posteroventral blade like structures are present,resembling paired haemapophyses. The subcentral foramina faces antero-ventrally near to the base of haemapophyses. Prezygapophyses are short and more laterally oriented, with little or no inclination. The neural spine is a relatively high lamina, considerably different from the neural spine shape of Colombophis spp. Ontogenetic variation Most of the specimens belong to adults as they are fully ossified and present a medium to large size. However, VPPLT-1006 specimen (Fig. 3A, B), may represent a juvenile or sub adult individual based on its small size and the ovoid shape of the cotyle (Hsiou et al. 2010), it also lacks a developed prezygapophyseal processes, it has a narrow zygosphene and a relatively large neural canal as it happens in extant and ancient snake neonates (LaDuke 1991; Xing et al. 2018). Parazygantral foramina Parazygantral foramina are present in both species of Colombophis, but only in two specimens (VPPLT-1728 and VPPLT-1740), as well as in the holotype MNHN-VIV-6 (Figs 4A, B; 6A, B; 7). These structures appear as a single foramen with or without small pits aside, which are interconnected internally with the foramen, (Fig. 8). Pits may appear also in specimens with no clearly defined foramen (Figs 6C; 8E, F). The internal structure of the vertebrae reveals that the dorso-posterior region of the vertebra (postzygapophyses and neural arch) is highly vascularized, where the parazygantral foramina and its associated pits are interconnected with the zygantral and lateral foramina. This feature is particularly visible in VPPLT-1728 specimen, where the internal structure is infilled with a denser material that creates a perfect endocast of the vertebra (Fig. 8G, H)., Published as part of Alfonso-Rojas, Andrés, Vanegas, Rubén D., Mariño-Morejón, Elizabeth & Cadena, Edwin-Alberto, 2023, Newly discovered fossils provide novel insights on the biology of the South American Miocene snake Colombophis Hoffstetter & Rage, 1977, pp. 377-399 in Geodiversitas 45 (13) on pages 382-385, DOI: 10.5252/geodiversitas2023v45a13, http://zenodo.org/record/8157175, {"references":["HOFFSTETTER R. & RAGE J. C. 1977. - Le gisement de vertebres miocenes de la Venta (Colombie) et sa faune de serpents. Annales de Paleontologie (Vertebres) 63 (2): 161 - 190.","HSIOU A. S., ALBINO A. M. & FERIGOLO J. 2010. - Reappraisal of the south American Miocene snakes of the genus Colombophis, with description of a new species. Acta Palaeontologica Polonica 55 (3): 365 - 379. https: // doi. org / 10.4202 / app. 2009.1111","LADUKE T. C. 1991. - The fossil snakes of pit 91, Rancho La Brea, California. Contributions in Science 424: 1 - 28. https: // doi. org / 10.5962 / p. 226807","XING L., CALDWELL M. W., CHEN R., NYDAM R. L., PALCI A., SIMOES T. R., MCKELLAR R. C., LEE M. S. Y., LIU Y., SHI H., WANG K. & BAI M. 2018. - A mid-Cretaceous embryonic-toneonate snake in amber from Myanmar. Science Advances 4 (7): https: // doi. org / 10.1126 / sciadv. aat 5042"]}

Colombophis spinosus Hsiou, Albino & Ferigolo, 2010 (Fig. 6) Colombophis spinosus Hsiou, Albino & Ferigolo, 2010: 371. REVISED DIAGNOSIS. — Fossil snake with similar characteristics of C. portai but differs as most vertebrae are significantly shorter than high (pr-po, Published as part of Alfonso-Rojas, Andrés, Vanegas, Rubén D., Mariño-Morejón, Elizabeth & Cadena, Edwin-Alberto, 2023, Newly discovered fossils provide novel insights on the biology of the South American Miocene snake Colombophis Hoffstetter & Rage, 1977, pp. 377-399 in Geodiversitas 45 (13) on page 382, DOI: 10.5252/geodiversitas2023v45a13, http://zenodo.org/record/8157175, {"references":["HSIOU A. S., ALBINO A. M. & FERIGOLO J. 2010. - Reappraisal of the south American Miocene snakes of the genus Colombophis, with description of a new species. Acta Palaeontologica Polonica 55 (3): 365 - 379. https: // doi. org / 10.4202 / app. 2009.1111"]}

A redescription of the extinct snake genus Colombophis is presented, on the basis of new specimens from the late Miocene of southwestern Brazilian Amazonia, and those previously reported for the middle Miocene of Colombia and Venezuela. The reappraisal of Colombophis allows the recognition of a new species, C. spinosus sp. nov. The revised diagnosis of the genus is based on the midtrunk vertebrae, distinct from those of other snakes mainly in the features of the neural arch, position and shape of the neural spine, inclination of the zygapophyses, shape of the centrum, and development of the haemal keel. The affinities of Colombophis with “Anilioidea” are still unresolved; it is distinguished from all known extinct and extant “anilioids” due to its great vertebral size and the frequent presence of paracotylar foramina. The posterior paired apophyses of the haemal keel in some vertebrae, and the high neural spine of C. spinosus also contrast significantly with the “anilioid” genera, making the allocation of the genus into this probably paraphyletic group not well supported. Here, we recognized Colombophis as a basal alethinophidian of uncertain relationships.