[D] Ceratosaurus sp.
Describer
Mateus, Walen and Antunes 2006
Time
Jurassic Late Kimmeridgian
Classification
Saurischia Theropoda Ceratosauria
Diet
Carnivore
Fossilsite
Lourinha Formation, Portugal
Fall Under
Ceratosaurus
Info
Ceratosaurus (Marsh, 1884) > Ceratosaurus nasicornis (Marsh, 1884) Ceratosaurus ingens (Janensch, 1920) = Megalosaurus ingens (1) (Janensch, 1920)
Ceratosaurus (Marsh, 1884) > Ceratosaurus willisobrienorum (Welles, Powell & Pickering, vide Pickering, 1995) = Ceratosaurus dentisulcatus (Madsen & Welles, 2000) = Ceratosaurus magnicornis (Madsen & Welles, 2000)
Ceratosaurus (Marsh, 1884) > Ceratosaurus sp. Mateus, Walen and Antunes 2006)
The material from Portugal was collected in Lourinhã Municipality (right femur and left tibia ML352 from Rodela do Valmitão, figure 2, tooth ML809 from Porto das Barcas, tooth ML737 from Peralta and tooth ML342 from Merendeiro. The most identifiable material is from the Praia da Amoreira Member, in the lower part of the Lourinhã Formation (Kimmeridgian).
The right femur ML352 is 64.7 cm long which allows a body weight estimate (based on Anderson et al., 1985) of about 560 kg, which is within the range of most Ceratosaurus specimens from the Morrison Formation. The specimen ML352 is clearly from Ceratosaurus. Similarities include: presence of a trochanteric shelf; anterior trochanter not bladeshaped; femoral head projects anteromedially; deep sulcus along lateral side of the crista tibiofibularis; lack of the lateral longitudinal groove at the distal end of tibia; the femoral head is projected anteromedially (Mateus and Antunes, 2000a; Antunes and Mateus, 2003; and compare with Gilmore, 1920, and Madsen and Welles, 2000; figure 3, 4 and 5).
Minor differences from Ceratosaurus nasicornis are the more developed fibular crest, and the distal femoral head projects to form a notch that is more developed in ML352. Laterally, the head has a small caudal projection as in Ceratosaurus nasicornis and Coelophysis. In ML352, there is a small depression between the greater trochanter and the femoral head. In the Portuguese Ceratosaurus, the distal end of the femur has a bridge between the two condyles at the posterior (flexor) groove. Such a feature is present but in the Ceratosauria (Megapnosaurus, Carnotaurus, Ceratosaurus dentisulcatus).
The lingual facets of the anterior teeth bear longitudinal grooves, as in Morrison Ceratosaurus dentisulcatus. The relative position of the epiphysial expansions in ML352 is different from Ceratosaurus nasicornis and Ceratosaurus magnicornis in being closer to those of Ceratosaurus dentisulcatus, where the distal and proximal expansions turn more from position by the diaphysial axis. The posterior intercondylar bridge of the femur is also present in Ceratosaurus dentisulcatus but is absent in the other species of the genus. Accordingly, we may conclude that the Portuguese species is a Ceratosaurus sp. closer to Ceratosaurus dentisulcatus, rather than to Ceratosaurus nasicornis or Ceratosaurus magnicornis. (Mateus, Walen and Antunes 2006)
Mateus, Walen and Antunes 2006
Time
Jurassic Late Kimmeridgian
Classification
Saurischia Theropoda Ceratosauria
Diet
Carnivore
Fossilsite
Lourinha Formation, Portugal
Fall Under
Ceratosaurus
Info
Ceratosaurus (Marsh, 1884) > Ceratosaurus nasicornis (Marsh, 1884) Ceratosaurus ingens (Janensch, 1920) = Megalosaurus ingens (1) (Janensch, 1920)
Ceratosaurus (Marsh, 1884) > Ceratosaurus willisobrienorum (Welles, Powell & Pickering, vide Pickering, 1995) = Ceratosaurus dentisulcatus (Madsen & Welles, 2000) = Ceratosaurus magnicornis (Madsen & Welles, 2000)
Ceratosaurus (Marsh, 1884) > Ceratosaurus sp. Mateus, Walen and Antunes 2006)
The material from Portugal was collected in Lourinhã Municipality (right femur and left tibia ML352 from Rodela do Valmitão, figure 2, tooth ML809 from Porto das Barcas, tooth ML737 from Peralta and tooth ML342 from Merendeiro. The most identifiable material is from the Praia da Amoreira Member, in the lower part of the Lourinhã Formation (Kimmeridgian).
The right femur ML352 is 64.7 cm long which allows a body weight estimate (based on Anderson et al., 1985) of about 560 kg, which is within the range of most Ceratosaurus specimens from the Morrison Formation. The specimen ML352 is clearly from Ceratosaurus. Similarities include: presence of a trochanteric shelf; anterior trochanter not bladeshaped; femoral head projects anteromedially; deep sulcus along lateral side of the crista tibiofibularis; lack of the lateral longitudinal groove at the distal end of tibia; the femoral head is projected anteromedially (Mateus and Antunes, 2000a; Antunes and Mateus, 2003; and compare with Gilmore, 1920, and Madsen and Welles, 2000; figure 3, 4 and 5).
Minor differences from Ceratosaurus nasicornis are the more developed fibular crest, and the distal femoral head projects to form a notch that is more developed in ML352. Laterally, the head has a small caudal projection as in Ceratosaurus nasicornis and Coelophysis. In ML352, there is a small depression between the greater trochanter and the femoral head. In the Portuguese Ceratosaurus, the distal end of the femur has a bridge between the two condyles at the posterior (flexor) groove. Such a feature is present but in the Ceratosauria (Megapnosaurus, Carnotaurus, Ceratosaurus dentisulcatus).
The lingual facets of the anterior teeth bear longitudinal grooves, as in Morrison Ceratosaurus dentisulcatus. The relative position of the epiphysial expansions in ML352 is different from Ceratosaurus nasicornis and Ceratosaurus magnicornis in being closer to those of Ceratosaurus dentisulcatus, where the distal and proximal expansions turn more from position by the diaphysial axis. The posterior intercondylar bridge of the femur is also present in Ceratosaurus dentisulcatus but is absent in the other species of the genus. Accordingly, we may conclude that the Portuguese species is a Ceratosaurus sp. closer to Ceratosaurus dentisulcatus, rather than to Ceratosaurus nasicornis or Ceratosaurus magnicornis. (Mateus, Walen and Antunes 2006)