Open Paleo

Riojavenatrix

Isasmendi et al., 2024 ree-YO-ha-VEH-nuh-trix

Named for La Rioja Province, Spain, where the fossils were found, combined with Latin 'venatrix' meaning 'huntress'; meaning 'La Rioja huntress.'

121.4–113.2 million years ago Aptian, Early Cretaceous
Early Cretaceous stages

Riojavenatrix is a genus of spinosaurid theropod dinosaurs from the Early Cretaceous Enciso Group of La Rioja, Spain. The type species is Riojavenatrix lacustris.

Under dispute

Riojavenatrix lacustris is an unstable spinosaurid; its describing analysis (Isasmendi and colleagues, 2024) prefers a baryonychine placement, and Rauhut and colleagues (2025) recover it as a baryonychine under implied weights, but both find it can also fall among early-branching spinosaurines. Spinosauridae is the least-inclusive clade both subfamily hypotheses accept.

Diagnosis

  1. Lateromedially thick and triangular pubic boot with straight posterolateral margin
  2. Anteroposteriorly expanded ischial boot with anterodorsally oriented tip and angular anterodistal surface
  3. Narrow, restricted articular groove on femoral head proximal surface, anteromedially–posterolaterally inclined
  4. Medial femoral condyle with only slight posteromedial orientation of long axis
  5. Vertical ridge on medial margin of astragalus ascending process
  6. Height of astragalus ascending process more than twice the astragalar body height
  7. Anterior depression with dorsally located foramen on lateral surface of calcaneum

Species

Riojavenatrix lacustris Isasmendi et al., 2024

Type species

From Latin 'lacustris' meaning 'of the lake' or 'from the lake', referring to the lacustrine depositional environment of the Enciso Group where the holotype was found.

Holotype
CPI 1637, CPI 1638, CPI 1639A, CPI 1639B, CPI 1640, CPI 1641A, CPI 1641B, CPI 1642, CPI 1643, CPI 1644, CPI 1645, CPI 1646, CPI 1647, CPI 1648, CPI 1675A, CPI 1675B, CPI 1676, CPI 1677 , Centro de Interpretación Paleontológica de La Rioja
Material
Partial skeleton of a single individual
Horizon
Enciso Group, Aptian, Early Cretaceous , 121.4–113.2 million years ago
Locality
Virgen del Villar-1, La Rioja, Spain

References

  1. Isasmendi, E.; Cuesta, E.; Díaz-Martínez, I.; Company, J.; Sáez-Benito, P.; Viera, L. I.; Torices, A.; Pereda-Suberbiola, X. (2024). Increasing the theropod record of Europe: a new basal spinosaurid from the Enciso Group of the Cameros Basin (La Rioja, Spain). Evolutionary implications and palaeobiodiversity. Zoological Journal of the Linnean Society 202(3). Oxford University Press (OUP). doi:10.1093/zoolinnean/zlad193

    Describing paper; erected Riojavenatrix as a baryonychine, though its analysis also recovered an early spinosaurine position.

    isasmendi2024a
  2. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the body length estimate.

    jones2026c
  3. Rauhut, O. W. M.; Canudo, J. I.; Castanera, D. (2025). Revision of the theropod dinosaur Camarillasaurus cirugedae from the Early Cretaceous (Barremian) of Teruel province, Spain. Palaeontologia Electronica 28(3): 1-67. doi:10.26879/1543

    Recovered Riojavenatrix as a baryonychine under implied weights; under equal weights it floated among baryonychines and early spinosaurines.

    rauhut2025a