A new fossil MP111209-1 found in the Barremian beds of Sáchica, a town near Villa de Leiva representing the more complete skeleton found in the region is described here. After a detailed study of its morphological characteristics, it is evident that the new specimen represents a new genus and species of brachauchenine pliosaurid from Central Colombia that we named Sachicasaurus vitae gen. et sp. nov. Sachicasaurus is a large brachauchenine (almost 10 m in length) characterized by the following combination of characters: skull exceeding two meters in length, transverse constriction in the rostrum, caniniform teeth present, pineal foramen in a very advanced position, palatines separated in the midline by the pterygoids, very short mandibular symphysis (bearing four teeth positions), reduced number of mandibular teeth (less than 20), slender hyoid bones, 12 cervical vertebrae, cervical centra showing ventral foramina, single rib facet in all cervical centra, at least 40 pre-caudal vertebrae, and ilium with a long posterior projection. Although it is difficult to clearly establish the phylogenetic position of Sachicasaurus viate within Brachaucheninae due to its combination of primitive and derived features, the morphological comparisons and the cladistic analysis show an evident phylogenetic proximity of Sachicasaurus to the Aptian-Albian genus Kronosaurus.

A new specimen of Stenorhynchosaurus munozi Páramo-Fonseca et al., 2016 (Plesiosauria, Pliosauridae), found at Sáchica (Boyacá, Colombia) in upper Barremian beds of the Arcillolitas Abigarradas Member of the Paja Formation, is described herein. It consists of a complete skull and 10 cervical vertebrae of an adult individual and provides valuable new morphological information on the species: the presence of nasals covering a subsurface circular cavity where salt glands were probably lodged (new autapomorphy), the presence of a high sagittal crest on the parietal, a very elongated pineal foramen enclosed entirely within the parietals, and unfused neural arches in the cervical vertebrae. A phylogenetic analysis supports the inclusion of Stenorhynchosaurus munozi within the pliosaurid clade Brachaucheninae. A morphological comparison between the juvenile and adult stages of S. munozi shows that in the adult stage, the margins of the internal nares and the anterior part of the anterior interpterygoid vacuity are well ossified, the medial joints of the pterygoids and the mandibular symphysis are closed, and the atlas and the axis are fused, but the cervical neural arches remain unfused to the centra. The growth pattern of the skull dorsal bones differs from that of the palatal elements, but the relative distance between the external and internal nares remains the same. A greater longitudinal growth in the skull and a negative allometric orbital growth pattern results in a proportionally longer skull and relatively smaller orbits in the adult.

Stenorhynchosaurus munozi, gen. et sp. nov. a new pliosaurid from the Upper Barremian (Lower Cretaceous) of Villa de Leiva, Colombia, South America

The extinct neoteleost family Dercetidae includes elongate, long-jawed marine fishes that are known from the Late Cretaceous to Paleocene in deposits from the Levant, Europe, North Africa, England, Mexico and Brazil. The fossil record of the family in South America is very sparse and previously was restricted to outcrops in Brazil. Herein we describe a new dercetid fish from the Turonian of Colombia, †Candelarhynchus padillai gen. et sp. nov. A single articulated specimen is preserved in part and counterpart; the posterior part of the fish is missing. The specimen differs from other dercetid species by the following unique combination of morphological features: lack of scutes on the flanks of the body, presence of a single pair of transverse processes associated with the abdominal vertebrae, roofed posttemporal fossa, single row of small conical teeth on the dentary and maxilla, toothless premaxilla ornamented with pronounced longitudinal striations and protruding forward far beyond the anterior end of the dentary, and relatively large pectoral fins positioned high on the body. When included in a phylogenetic analysis of †Enchodontoidei, †C. padillai gen. et sp. nov. falls within a monophyletic family Dercetidae and is placed as sister taxon to the Late Cretaceous dercetid †Hastichthys from Israel, indicating faunal connections between the Eastern and Western Tethys. The new taxon provides novel insights into the distribution of dercetid fishes in the Western Tethys region during the early Late Cretaceous. http://zoobank.org/urn:lsid:zoobank.org:pub:29F97139-98BD-48E5-AAC0-091980F866E2

ESTADO ACTUAL DEL CONOCIMIENTO DE LOS REPTILES MARINOS CRETÁCICOS DE COLOMBIA

In this paper, we describe a new ophthalmosaurid specimen found in the lower Barremian beds of the Paja Formation at Villa de Leiva, Boyacá, Colombia. The specimen represents a new species of Platypterygius, P. elsuntuoso sp. nov. defined by three unique features within the genus: a small ventral peg in the anterior ventral border of the extracondylar area of the basioccipital; a supratemporal groove in the quadrate; and a shallow neck at the base of the acellular cementum ring on the teeth root. In support of our taxonomic determination, in this contribution we also assess the species composition of the genus Platypterygius, comparing the known anatomy of the type species P. platydactylus with that of the other species previously assigned to the genus. We found that a great morphological affinity in the forelimb of the species P. americanus, P. australis, P. hercynicus, and P. sachicarum (lower Barremian to lower Cenomanian) with that of the type species (Aptian) is unquestionable and differentiate them from all other ophthalmosaurids. Three new diagnostic features (synapomorphies of the genus) support their inclusion in Platypterygius. Consequently, the genus name “Kyhytysuka”, recently proposed to differentiate P. sachicarum from the genus Platypterygius is here rejected. A careful comparison of the cranial characteristics of Platypterygius specimens preserving associated cranial and fin remains demonstrate that Platypterygius is a genus distinguishable from other ophthalmosaurids not only by a typical forelimb but also by a particular combination of skull features. In this context, the skull morphology of “Simbirskiasaurus” concurs with that defining Platypterygius and its minor differences are not sufficient to support its generic distinction. The morphological comparisons and our phylogenetic analysis show the new species P. elsuntuoso more closely related to the Colombian species P. sachicarum than to other species of Platypterygius. Given that the new species came from the lower Barremian and P. sachicarum came from the upper Barremian, the minor differences in dentition found between the two species suggest a speciation by adaptation to new food sources in the Cretaceous epicontinental sea of Colombia.