Christoph Grünwald

• Bachelor of Applied Science
• Managing Director at HERP.MX

Garter snakes in the genus Thamnophis from Mexico have a long and convoluted taxonomic history. From 2015 to 2022, we conducted a comprehensive sampling of Mexican Thamnophis species, aiming to link molecular phylogenies with the recognized species related to T. scalaris in the highlands of Mexico. Here, we present an analysis of mitochondrial DNA...

Phylogenomics allows us to uncover the historical signal of evolutionary processes through time and estimate phylogenetic networks accounting for these signals. Insight from genome-wide data further allows us to pinpoint the contributions to phylogenetic signal from hybridization, introgression, and ancestral polymorphism across the genome. Here we...

Snake venom can vary both among and within species. While some groups of New World pitvipers—such as rattlesnakes—have been well studied, very little is known about the venom of montane pitvipers (Cerrophidion) found across the Mesoamerican highlands. Compared to most well-studied rattlesnakes, which are widely distributed, the isolated montane pop...

We describe a new species of Eleutherodactylus (subgenus Syrrhophus) from Guerrero, Mexico, based on morphological and molecular data, as well as advertisement call analysis. Eleutherodactylus franzi sp. nov. has unique features including widely expanded fingertips, indistinct, but visible lumbo-inguinal glands, an immaculate white venter and dark...

We describe a new saxicolous species of Lepidophyma from the Sierra Madre Oriental, in the state of Tamaulipas, Mexico and provide morphological and molecular data to support the novelty of this species. The new species is most closely related to members of the L. sylvaticum group; however; it is a flattened form specialised for a saxicolous lifest...

Beyond providing critical information to biologists, species distributions are useful for naturalists, curious citizens, and applied disciplines including conservation planning and medical intervention. Venomous snakes are one group that highlight the importance of having accurate information given their cosmopolitan distribution and medical signif...

The Eleutherodactylus subgenus Syrrhophus has a complex taxonomic history. For many years the species were classified into series and groups of species based on morphological and allozyme data. However, most of the species have conservative morphology, and their phylogenetic relationships have not been resolved. Furthermore, recent studies employin...

A new species of the Geophis dubius group is described from the cloud forests in the mountains north of Xalapa, Veracruz. This new species is most similar to G. turbidus and G. lorancai, from which it differs genetically as well as by a very unique color pattern, morphological characters, and habitat use. The validity of G. fuscus, which was descri...

Resumen (Spanish abstract)—Documentamos una nueva localidad para Kinosternon alamosae, este registro representa el segundo para el estado de Sinaloa y el primero para el municipio de Ahome, con una extensión geográfica de 222 km (línea aérea) norte de la localidad más cercana al sur en del municipio de Culiacán y 113 km (línea aérea) sur de la loca...

We describe two new species of Tropidodipsas related to the T. fasciata species group as defined by Kofron (1987), and provide morphological and molecular data to support the novelty of both species. A partial molecular phylogeny of the Mexican species of snail-eating snakes (Serpentes, Dipsadidae) is presented, and we discuss evolutionary relation...

Significance Why biological complexity evolves is a major question in the life sciences, but the specific selection pressures favoring simple or complex traits remain unclear. Using high-resolution measurements of venom complexity in North American pitvipers, we link changes in complexity to natural history via phylogenetic diversity of snake diets...

We describe a new species of mud turtle of the genus Kinosternon from the Pacific Coastal Plain of the Mexican states Sinaloa and Nayarit. The new species shares morphological characters with the recently described Kinosternon vogti, which are unique to these two turtles and separate them from the other species of the genus. The new species differs...

SINALOA: Municip ali ty of Concordia: 4.8 km E of Copalá on Hwy. 40 (Mazatlán–Durango Highway) (23.40040°N, 105.91569°W; WSG 84), 541 m elev. 16 August 2015. J. A. Loc-Barragán, H. Franz- Chávez, A. J. Grünwald, and C. I. Grünwald. Verified by Jacobo Reyes-Velazco. Herpetological Collection, Museum of Zoology, Faculty of Sciences, UNAM (MZFC-HE 331...

On 7 November 2019, an adult female K. vogti (CIG-1614) drowned in a turtle trap in a drainage canal in the outskirts of Puerto Vallarta (20.7002°N, 105.2257°W) after the string that was holding the trap partially above water broke. The measurements for this individual are as follows: carapace length 96 mm, carapace width 7.5 mm, plastron length 83...

Mexico: Nayarit: Municipality of El Nayar, on Federal Road 44 (Ruiz, Nayarit-Fresnillo, Zacatecas), 2.3 km south of the Zacatecas border and 2.5 km south of the Durango border (22.381564°N, 104.348159°W; WGS84; 2244 m elevation), 30 June 2018. This specimen (Fig. 1) represents the southeasternmost record for the species and the first record from th...

Based on morphological data collected from treefrogs related to Sarcohyla hazelae, we describe a new species of the genus Sarcohyla from the cloud forest of the Sierra Madre del Sur of Guerrero, Mexico. We compare physical charactersitics of this new species to its closest relatives within the genus Sarcohyla, including dorsal and ventral coloratio...

Resumen.-A partir del trabajo de campo aumentamos la distribución conocida de Cerrophidion petlalcalensis, una víbora de foseta endémica de México cuya distribución fue subestimada durante muchos años. Reportamos esta especie por primera vez para el estado de Oaxaca, y presentamos datos de historia natural y la distribución potencial de la especie...

From 2011 to 2019, we visited 11 localities within the municipality of Huajicori in the state of Nayarit, Mexico, adjacent to natural vegetation such as low tropical deciduous forest, oak forest, oak-pine forest, and pine forest. We have found 21 amphibian and 35 reptile species, for a total 56 species, with 31 endemic to the country. Twenty-one of...

Venoms of the three species of Ophryacus (O. sphenophrys, O. smaragdinus, and O. undulatus), a viperid genus endemic to Mexico, were analyzed for the first time in the present work. The three venoms lacked procoagulant activity on human plasma, but induced hemorrhage and were highly lethal to mice. These venoms also displayed proteolytic and phosph...

Plectrohyla avia is a poorly known Critically Endangered species from Southern Mexico and Guatemala.Herein we describe its aquatic reproductive behavior, including underwater calling and odd adaptations for aquatic life. This is the first Hylid species (aside Pseudinae) to be adapted for aquatic breeding.

Members of the Crotalus triseriatus species group of montane rattlesnakes are widely distributed across the highlands of Mexico and southwestern USA. Although five species are currently recognized within the group, species limits remain to be tested. Genetic studies suggest that species may be paraphyletic and that at least one cryptic species may...