Boidae

72nd Annual Meeting of the Society of vertebrate Paleontology. Program and Abstracts, 2012:108.

Titanoboa cerrejonensis from the Cerrejón Formation (middle to late Paleocene; 58-60 My) of Colombia, is the largest known snake. The taxon was originally diagnosed, assigned to the clade Boinae, and estimated to be approximately 12.8 m (±2.18 m) in total body length on the basis of precloacal vertebral morphology and size, but the absence of cranial remains prohibited a more precise size estimate and robust phylogenetic hypothesis. Recent fieldwork in the type locality has resulted in the recovery of several new specimens of Titanoboa including parts of the cranium and mandible (maxillae, palatine, pterygoid, quadrate, dentary, and compound elements) associated with partial axial skeletons. We estimate skull length from cranial elements to be 40 cm, corresponding to a total body length of 14.3 m (±1.28 m) based on the scaling relationship of head length to body length in the extant boine Eunectes. Phylogenetic analyses of Titanoboa and extant macrostomatan snakes using cranial and postcranial osteology, and including analyses incorporating a molecular scaffold for extant taxa, supports boine affinities of Titanoboa, based on the extreme reduction of the palatine choanal and posteromedial processes as well as vertebral anatomy. Within Boinae, Titanoboa shares a close relationship with Pacific Island-Madagascan taxa. These results are the first historical evidence linking Neotropical and Old World boines, and constrain divergence timing of the clades to no younger than 58 My. Cranial elements of Titanoboa possess unique features relative to other boids, including high palatal and marginal tooth position counts, low-angled quadrate orientation, and reduced palatine-pterygoid and pterygoid-quadrate articulations. These characters, combined with weakly ankylosed teeth in Titanoboa, are characteristic of piscivorous feeding ecology in extant caenophidian snakes. Preservation in the large-scale fluvial depositional environments of the Cerrejón Formation, combined with the recovery of associated fossils of large dipnoan and osteoglossomorph fishes, also suggests a dominantly piscivorous feeding ecology for Titanoboa, which is unique among living and fossil boids.

Cryptosporidium is an important enteric pathogen that infects a wide range of humans and animals. Rapid and reliable detection and characterisation methods are essential for understanding the transmission dynamics of the parasite. Sanger sequencing, and high-throughput sequencing (HTS) on an Ion Torrent platform, were compared with each other for their sensitivity and accuracy in detecting and characterising 25 Cryptosporidium-positive human and animal faecal samples. Ion Torrent reads (n = 123,857) were obtained at both 18S rRNA and actin loci for 21 of the 25 samples. Of these, one isolate at the actin locus (Cattle 05) and three at the18S rRNA locus (HTS 10, HTS 11 and HTS 12), suffered PCR drop-out (i.e. PCR failures) when using fusion-tagged PCR. Sanger sequences were obtained for both loci for 23 of the 25 samples and showed good agreement with Ion Torrent-basedgenotyping. Two samples both from pythons (SK 02 and SK 05) produced mixed 18S and actin chromatograms by Sanger sequ...