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Bison antiquus Leidy, 1852 was one of the largest and most widely distributed megafaunal species during the Late Pleistocene in North America, giving rise to the modern plains bison in the middle Holocene. Despite the importance of the ancient bison, little is known about its feeding ecology. We employed a combination of extended mesowear, and mesowear III to infer the dietary preference and habitat use of three Mexican samples of B. antiquus. These included two northern samples—La Piedad-Santa Ana and La Cinta-Portalitos—from the Transmexican Volcanic Belt morphotectonic Province, as well as one southern sample—Viko Vijin—from the Sierra Madre del Sur morphotectonic province. We found that the northern Mexican samples were primarily nonstrict grazers, whereas the southern sample displays a pattern consistent with mixed feeding habits. This suggests variability among the diets of the bison from these samples, caused by different paleoenvironments. This evidence complements the paleoenvironmental reconstructions in the studied localities; for the northern samples, open prairies composed of patches of woodland or shrubland and, for the southern locality, a fluvial floodplain with short-lived vegetation. In both scenarios, grasses (Poaceae) were nondominant. The dietary habits of our samples of ancient bison in Mexico are the southernmost dietary inference for the species in North America and expand our knowledge of the dietary habits of B. antiquus during the Late Pleistocene.

Taxonomía y sistemática Una especie nueva de alacrán del género Centruroides (Scorpiones: Buthidae) del noroeste de México A new species of the scorpion genus Centruroides (Scorpiones: Buthidae) from northwestern Mexico

Revista Mexicana de Biodiversidad www.ib.unam.mx/revista/ Revista Mexicana de Biodiversidad 87 (2016) 49-61 Taxonomy and systematics A new species of scorpion of the genus Centruroides (Scorpiones: Buthidae) from the state of Michoacán, Mexico Una especie nueva de alacrán del género Centruroides (Scorpiones: Buthidae) del estado de Michoacán, México

This study investigated the presence of nontuberculous mycobacteria (NTM) for the first time in two types of unpasteurized fresh cheese produced in the state of Michoacan, Mexico. We tested for this pathogen along with the others to broaden the study of microbiological quality in a total of 60 samples of cheese, 30 fresh and 30 adobera, which were collected from six artisanal cheese factories (ACF). The hygienic conditions of these establishments and the practices of cheese manufacture were generally poor. Although Mycobacterium bovis was not detected, four cheese samples harbored NTM isolates. The four NTM isolates were identified using three molecular markers (hsp65, rrs and rpoB genes) which corresponded to Mycolicibacterium fortuitum (n=3) and Mycolicibacterium mageritense (n=1). All 60 cheese samples analyzed had unsatisfactory microbiological quality according to the Mexican Official Guideline. Regarding fresh cheeses, all 30 samples analyzed were positive for aerobic mesophilic bacteria (AMB), total coliforms (TC), fecal coliforms (FC) and yeasts and moulds. Escherichia coli and Staphylococcus aureus were present in 23 and 21 samples, respectively. Listeria monocytogenes was identified in a sample and was isolated from a bulk milk tank in the same ACF. With regard to adobera cheeses, all samples were positive for AMB, TC, FC, yeasts and moulds and S. aureus. E. coli was isolated from 28 samples. Salmonella was isolated from a sample and also from a wooden shovel used in the manufacture of the cheeses in the same ACF. Thus, the consumption of unpasteurized fresh cheese may represent a public health risk. Because of this, health authorities should enforce the legislation that forbids the processing of cheese with unpasteurized milk and encourage producers to follow good manufacturing practices from original ingredients all the way through the production process of the cheese to its sale, in order to assure a safe product.