Open Paleo

Losillasaurus

Casanovas et al., 2001 loh-SIL-yah-SAWR-us

Named after Losilla, the village near the fossil locality in Valencia, Spain; meaning "Losilla lizard"

154.8–143.1 million years ago Kimmeridgian–Tithonian, Late Jurassic
Late Jurassic stages

Losillasaurus is a genus of turiasaurian sauropod dinosaur from the Late Jurassic and possibly Early Cretaceous (Kimmeridgian-?Berriasian) of southeastern Spain. The type species, Losillasaurus giganteus, was discovered in the Villar del Arzobispo Formation in Valencia, and formally described by Casanovas, Santafé, and Sanz in 2001. The holotype material is from a subadult and includes part of a skull; complete cervical, dorsal, sacral, and caudal vertebrae as well as several fragments; skeletal elements from the limbs including a humerus, ulna, radius, and metacarpal; sternal plates; and from the pelvis: the ilium, ischium, and pubis. The genus is characterized by the dimension and shape of the neural spine of the proximal caudal vertebrae. The humerus is 143 centimeters (56 in) long, which despite being from a subadult specimen is within 20% of the size of Paralititan. The size estimation proposed by Francisco Gascó in a master's thesis is 15-18 m (49-59 ft) in length and 12-15 t (13-17 short tons) in body mass.

Diagnosis

  1. Neural spines of proximal caudal vertebrae arched dorsocaudally in lateral view (cutlass shaped)
  2. Ratio of craniocaudal dimension of neural spine base to total height approximately 0.50
  3. Middle and caudal dorsal vertebral centra opisthocoelous
  4. Ventral median keels on cervical centra reduced or absent
  5. Pleurocoels present in dorsal vertebral centra

Species

Losillasaurus giganteus Casanovas et al., 2001

Type species

From Latin 'giganteus' meaning 'gigantic', referring to the large size of this sauropod, whose humerus alone measures 143 centimeters.

Holotype
Lo-5 , Museo de Ciencias Naturales de Valencia
Material
Procoelous proximal caudal vertebral centrum; length/height ratio >0.5 < 0.6; neural spine transversely compressed and cutlass shaped; caudal ribs wing shaped (specimen Lo-5)
Horizon
Villar del Arzobispo Formation, Kimmeridgian–Tithonian, Late Jurassic , 154.8–143.1 million years ago
Locality
La Cañada, Valencia, Spain

References

  1. Casanovas, M. L.; Santafé, J. V.; Sanz, J. L. (2001). Losillasaurus giganteus, un nuevo saurópodo del tránsito Jurásico-Cretácico de la cuenca de "Los Serranos" (Valencia, España) [Losillasaurus giganteus, a new sauropod from the Jurassic-Cretaceous transition of the "Los Serranos" basin (Valencia, Spain)]. Paleontologia i Evolucio 32-33: 99-122. casanovas2001a
  2. Royo-Torres, R.; Cobos, A.; Mocho, P.; Alcalá, L. (2020). Origin and evolution of turiasaur dinosaurs set by means of a new 'rosetta' specimen from Spain. Zoological Journal of the Linnean Society 191(1): 201-227. Oxford University Press (OUP). doi:10.1093/zoolinnean/zlaa091

    Redescribes the genus and states the type horizon the erecting paper left open — "La Cañada site (Valencia), Villar del Arzobispo Formation", dated Kimmeridgian.

    royo-torres2020a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Sauropods. Princeton University Press.

    Source of the hip height estimate.

    jones2026b