Open Paleo

Mexidracon

Serrano-Brañas et al., 2025 MEK-si-DRAY-kon

From 'Mexi-' (referring to Mexico) and Greek 'drakon' (dragon or serpent); meaning 'Mexican dragon'.

83.6–72.2 million years ago Campanian, Late Cretaceous
Late Cretaceous stages

Mexidracon is an extinct genus of ornithomimid theropod dinosaurs from the late Cretaceous Cerro del Pueblo Formation of Coahuila, Mexico. The genus contains a single species, M. longimanus, known from a partial skeleton. Mexidracon is the second ornithomimosaur to be named from this formation, following the deinocheirid Paraxenisaurus in 2020.

Diagnosis

  1. Extreme elongation of metacarpus: metacarpal III length is 1.1 times humeral length, 1.072 times metatarsal II length, and 1.018 times metatarsal IV length.
  2. Proximal end of metacarpal II with a narrow subtriangular outline.
  3. Iliac pubic peduncle with a flared, zig-zag shaped articular margin that is wider anteriorly than posteriorly.
  4. Distal end of pubis with distal margin of anterior expansion separated from shaft by a deep notch.
  5. Ilium with ischiadic peduncle slightly longer proximodistally than pubic peduncle.
  6. Deeply concave iliac brevis fossa expanded posteriorly, overhanging the lateral surface of the postacetabular process.

Species

Mexidracon longimanus Serrano-Brañas et al., 2025

Type species

From Latin 'longimanus' meaning 'long hand', referring to the extreme elongation of the metacarpals in the holotype.

Holotype
BENC 32/2-0001 , Benemérita Escuela Normal de Coahuila
Material
Partially articulated skeleton: several dorsal, sacral, and caudal vertebrae, haemal arches, left humerus, left metacarpals I-III, partial left and right pelvic girdles, complete left and partial right femur, complete left tibia and proximal right tibia, proximal left and right fibulae, distal tarsals 3-4, left metatarsals II-IV, four pedal phalanges.
Horizon
Cerro del Pueblo Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Loma Prieta, Coahuila, Mexico

References

  1. Serrano-Brañas, C. I.; Espinosa-Chávez, B.; de León-Dávila, C.; Maccracken, S. A.; Barrera-Guevara, D.; Torres-Rodríguez, E.; Prieto-Márquez, A. (2025). A long-handed new ornithomimid dinosaur from the Campanian (Upper Cretaceous) Cerro del Pueblo Formation, Coahuila, Mexico. Cretaceous Research 169: 106087. Elsevier BV. doi:10.1016/j.cretres.2025.106087 serrano-brañas2025a