Python Daudin, 1803

Szyndlar, Zbigniew & Georgalis, Georgios L., 2023, An illustrated atlas of the vertebral morphology of extant non-caenophidian snakes, with special emphasis on the cloacal and caudal portions of the column, Vertebrate Zoology 73, pp. 717-886 : 717

Python Daudin, 1803

Material examined.

Python bivittatus Kuhl, 1820 (ISEZ R/327; ISEZ R/461; NHMW 35675); Python curtus Schlegel, 1872 (MGPT-MDHC 106; MGPT-MDHC 107; NHMUK 1988.598); Python molurus (Linnaeus, 1758) (ISEZ R/460; MNCN 13816; SMF PH 184); Python regius (Shaw, 1802) (MGPT-MDHC 116; MGPT-MDHC 144; MGPT-MDHC 161; MGPT-MDHC 162; MGPT-MDHC 163; MGPT-MDHC 173; MGPT-MDHC 196; MGPT-MDHC 456; MNHW Reptilia -0326 [juvenile]; MNHW Reptilia -0327 [juvenile]; SMF PH 28; SMF PH 29; SMF PH 49; SMF PH 51; SMF PH 58 [juvenile]; SMF PH 222 [juvenile]; UMMZ 190750); Python sebae (Gmelin, 1789) (MGPT-MDHC 121; SMF PH 1 [baby]; ZFMK 5199).

Description (Figs 141-149).

Trunk vertebrae. Centrum much shorter than wide; cotyle and condyle orbicular; neural arch vaulted; posterior median notch of the neural arch deep; neural spine considerably higher than long (in Python curtus , two to almost three times higher than long); prezygapophyseal accessory processes vestigial or very short; shallow interzygapophyseal constriction; hypapophyses disappearing at the level of V 70 to V 80; haemal keel in more posterior vertebrae moderately or well developed, ridge-like ( Python curtus , Python regius ) or somewhat wider and less distinct ( Python bivittatus , Python molurus ); paracotylar foramina absent.

Trunk / caudal transition. A bulb-like, more or less prominent, haemal keel (it can be considered a hypapophysis in Python curtus ) appears in the last trunk vertebrae and then diminishes gradually and becomes flattened in succeeding cloacal vertebrae. In a specimen of Python molurus (ISEZ R/460), short haemapophyses appear on the second cloacal vertebra, then disappear, and reappear again on the last cloacal and first caudal vertebra; the two anteriormost cloacal vertebrae of this snake are fused and apparently pathologically affected. In other examined snakes, normally developed haemapophyses can appear on the first ( Python sebae ) or second to sixth caudal vertebrae ( Python bivittatus , P. regius , and P. molurus ); in the last case, traces of haemapophyses (keels bifurcated posteriorly into two minute spurs) can be seen on the preceding caudal vertebra. Posteriormost caudal vertebrae can be fused (e.g., in P. molurus ).

Number of vertebrae. Python bivittatus (ISEZ R/461): 344 (273+3+68); Python curtus (MGPT-MDHC 107): 211 (177+4+30, including a fusion of posteriormost caudal vertebrae); Python curtus (NHMUK 1988.598): 207+ (174+4+29+); Python curtus (MGPT-MDHC 106): 203 (170+4+29); Python molurus (ISEZ R/327): 317+ (257+4+56+); Python molurus (SMF PH 184): 349 (272+4+73, including a fusion of posteriormost caudal vertebrae); Python molurus (ISEZ R/460): 342 (272+4+66); Python regius (SMF PH 28): 239 (205+4+30); Python regius (SMF PH 29): 239 (206+4+29); Python regius (SMF PH 49): 242 (206+4+32 [posteriormost caudal vertebrae are fused]); Python regius (MNHW Reptilia -0326 [juvenile]): 251+ (209+5+37, including a fusion of posteriormost caudal vertebrae); Python regius (MGPT-MDHC 456): 249 (211+4+34, including a final fusion of posteriormost caudal vertebrae); Python regius (MGPT-MDHC 162): 245 (208+5+32, including a final fusion of posteriormost caudal vertebrae); Python regius (SMF PH 58 [juvenile]): 245+ (207+4+34+ [several caudal vertebrae are missing]); Python regius (MGPT-MDHC 173 [juvenile]): 241+ (213+4+24+ [posteriormost caudal vertebrae missing]); Python regius (MGPT-MDHC 163): 237 (204+4+29, including a final fusion of posteriormost caudal vertebrae); Python regius (MNHW Reptilia -0327 [juvenile]): 230+ (213+17 cloacal and caudal vertebrae+ [several caudal vertebrae are missing]); Python sebae (MGPT-MDHC 121): 278+ (274+4+[caudal vertebrae missing]); Python sebae (SMF PH 1 [baby]): 332 (280+4+68 [posteriormost caudal vertebrae are fused]).

Data from literature and unpublished data from personal communications: Python bivittatus : 327 trunk and cloacal vertebrae plus 93 caudal vertebrae (Jingsong Shi, unpublished data, personal communication to GLG); Python brongersmai Stull, 1938: 178-179 trunk vertebrae plus unknown number of cloacal and caudal vertebrae ( Tsuihiji et al. 2012); Python curtus : 162-180 trunk and cloacal vertebrae plus 31-36 caudal vertebrae (Jingsong Shi, unpublished data, personal communication to GLG); Python molurus : 372 trunk vertebrae plus 61 cloacal and caudal vertebrae ( Janensch 1906); Python molurus : 291 vertebrae in total, of which 70 caudal vertebrae ( Python tigris of Owen 1877); Python molurus : 274 trunk vertebrae plus 75 cloacal and caudal vertebrae ( Nopcsa 1923); Python molurus : 324-328 vertebrae in total ( Parmley and Reed 2003); Python molurus : 269 trunk vertebrae plus unknown number of cloacal and caudal vertebrae ( Tsuihiji et al. 2012); Python molurus : 259 trunk vertebrae plus 68 cloacal and caudal vertebrae ( Polly et al. 2001); Python molurus : 253 trunk vertebrae plus 72 cloacal and caudal vertebrae ( Python tigris of Fischer 1857); Python molurus : 4 cloacal and 59 caudal vertebrae ( Sood 1941); Python molurus : 366 trunk vertebrae plus 8 cloacal vertebrae (apparently erroneous) plus 61 caudal vertebrae ( Rochebrune 1881); Python regius : 281 trunk vertebrae plus 67 cloacal and caudal vertebrae ( Owen 1850); Python regius : 215 trunk vertebrae plus 33 cloacal and caudal vertebrae ( Polly et al. 2001); Python regius : 207-211 trunk and cloacal vertebrae plus 32-35 caudal vertebrae (Jingsong Shi, unpublished data, personal communication to GLG); Python sebae : 306 trunk vertebrae plus 62 cloacal and caudal vertebrae ( Janensch 1906); Python sebae : 283 trunk and cloacal vertebrae plus 75+ caudal vertebrae ( Alexander and Gans 1966); Python sebae : 333 trunk vertebrae plus unknown number of cloacal and caudal vertebrae ( Albrecht 1883); Python sebae : 287 trunk vertebrae plus unknown number of cloacal and caudal vertebrae ( Gasc 1974); Python sebae : 282 trunk vertebrae plus 63 cloacal and caudal vertebrae ( Nopcsa 1923); Python sebae : 302 trunk vertebrae plus 6 cloacal vertebrae (probably erroneous) plus 62 caudal vertebrae ( Rochebrune 1881).

The total value of 435 vertebrae for Python molurus by Rochebrune (1881) has been repeated in several subsequent works (e.g., Hoffmann 1890; Baur 1897; Janensch 1906; Simpson 1933; Angel 1950) as well as in popular literature, purportedly, as the highest number of vertebrae ever observed in living snakes (although, in any case, it does not surpass the respective number of the leptotyphlopid Rhinoleptus and the typhlopid Letheobia ). Subsequent observations made on the same material by Hoffstetter and Gasc (1969) did not confirm Rochebrune’s counting; consequently, the latter authors stated that the maximum value for recent snakes is "more than 400" (apparently unaware at that time of the respective numbers of Rhinoleptus and Letheobia ); in any case, a specimen of Python bivittatus reported above reached a total of 420 vertebrae. Again in the work of Rochebrune (1881), mistakes also apparently apply to the given number of cloacal vertebrae of Python sebae (6) and P. molurus (8) (see also "Parts of the vertebral column" above for a discussion on the erroneous counts of cloacal vertebrae in Rochebrune’s [1881] work). On the other side of the vertebral count spectrum, the lowest count of vertebrae for Python is observed in P. curtus and P. brongersmai .