[D] Astrodon nanus
Describer
Gilmore, 1921
Time
Cretaceous Early Hauterivian Barremian
Classification
Saurischia Sauropodomorpha Sauropoda Titanosauria Incertae Sedis
Diet
Herbivore
Fossilsite
Arundel Formation, Prince Georges County,, Maryland, US
Fall Under
Astrodon
Info
Astrodon (Johnston, 1859) (= Astrodonius, Kuhn, 1961 / Astrodontaurus Johnston, 1858 vide Kranz, 2004) > Astrodon johnstoni (Leidy, 1865) > Astrodon nanus (Gilmore, 1921) >> Pleurocoelus nanus (Marsh, 1888) Astrodon johnstoni (Leidy, 1865) > Astrodon altus (Gilmore, 1921) >> Pleurocoelus altus (Marsh, 1888)
Isolated elements of mote than 6 animals including cranial elements.
[Pleurocoelus-Astrodon cf. nanus; Glen Rose Fm. Texas, US; Aptian Albian Cretaceous Early]
USNM 4968, 4969, 4970, 5678(?), The syntype suite material is from Prince Georges County, Maryland and was collected in 1887 by J.B. Hatcher and did consists of several isolated vertebral centra. The original description was by Marsh in the American Journal of Science, volume 35, page 91, in 1888 as Pleurocoelus nanus
The skull is known only from a few disarticulated elements. Vertebral centra are present from all parts of the column, but only in the tail are there neural arches. Most of the limb and foot bones are known but all are disarticulated, so relative lengths cannot be determined.
Salgado, L., J. O. Calvo, and R. A. Coria. 1995. Relaciones filogenéticas de Pleurocoelus Marsh (Sauropoda). Resúmenes 11˚ Jornadas Argentinas de Paleontología de Vertebrados:34. San Miguel de Tucumán. [Phylogenetic relationships of Pleurocoelus Marsh (Sauropoda)
Translated by: Jeffrey A. Wilson University of Chicago Department of Organismal Biology & Anatomy July 1997
The genus Pleurocoelus was originally proposed by Marsh to include material from the Arundel Formation (Lower Cretaceous) of Maryland, United States. Marsh recognized two species, P. nanus and P. altus. The former is well represented by a collection of mostly disarticulated elements, while the latter is known from only a tibia and some isolated vertebrae. Moreover, the presence of the genus Pleurocoelus was mentioned in Middle Cretaceous strata in the central north and central west of Texas (Comanche Series, Trinity Group). A reinterpretation of material previously assigned to Pleurocoelus suggests that (1) P. nanus corresponds to a valid species; (2) P. altus does not appear to correspond to an adult of P. nanus, as was proposed be various authors; and (3) sufficient evidence does not exist to demonstrate that the Comanchean species and the Maryland species correspond to the same genus (Pleurocoelus).
Pleurocoelus was traditionally included in the family Brachiosauridae, extending the biochron of this family of sauropods. In a numerical analysis of characters considered from the material previously assigned to Pleurocoelus, P. nanus is found to be the sister group to titanosaurs. These taxa share, among others, the following characters: absence of phalangeal articular surfaces on the distal metacarpals, and a transversely expanded distal tibia. Pleurocoelus retains anterior caudal vertebrae with flattened articular faces. “Pleurocoelus” altus exhibits an anteroposteriorly expanded distal tibia, a character which is plesiomorphic for sauropods.
The species represented in the Comanchean are probably basal members of the Titanosauria , as they present slightly procoelous anterior caudal vertebrae, dorsal vertebrae with the infradiapophyseal laminae bifurcated at their base, and the presence of a centro-parapophyseal lamina. Ichnological evidence supports the existence of basal titanosaurs in North America during the Middle Cretaceous.
Gilmore, 1921
Time
Cretaceous Early Hauterivian Barremian
Classification
Saurischia Sauropodomorpha Sauropoda Titanosauria Incertae Sedis
Diet
Herbivore
Fossilsite
Arundel Formation, Prince Georges County,, Maryland, US
Fall Under
Astrodon
Info
Astrodon (Johnston, 1859) (= Astrodonius, Kuhn, 1961 / Astrodontaurus Johnston, 1858 vide Kranz, 2004) > Astrodon johnstoni (Leidy, 1865) > Astrodon nanus (Gilmore, 1921) >> Pleurocoelus nanus (Marsh, 1888) Astrodon johnstoni (Leidy, 1865) > Astrodon altus (Gilmore, 1921) >> Pleurocoelus altus (Marsh, 1888)
Isolated elements of mote than 6 animals including cranial elements.
[Pleurocoelus-Astrodon cf. nanus; Glen Rose Fm. Texas, US; Aptian Albian Cretaceous Early]
USNM 4968, 4969, 4970, 5678(?), The syntype suite material is from Prince Georges County, Maryland and was collected in 1887 by J.B. Hatcher and did consists of several isolated vertebral centra. The original description was by Marsh in the American Journal of Science, volume 35, page 91, in 1888 as Pleurocoelus nanus
The skull is known only from a few disarticulated elements. Vertebral centra are present from all parts of the column, but only in the tail are there neural arches. Most of the limb and foot bones are known but all are disarticulated, so relative lengths cannot be determined.
Salgado, L., J. O. Calvo, and R. A. Coria. 1995. Relaciones filogenéticas de Pleurocoelus Marsh (Sauropoda). Resúmenes 11˚ Jornadas Argentinas de Paleontología de Vertebrados:34. San Miguel de Tucumán. [Phylogenetic relationships of Pleurocoelus Marsh (Sauropoda)
Translated by: Jeffrey A. Wilson University of Chicago Department of Organismal Biology & Anatomy July 1997
The genus Pleurocoelus was originally proposed by Marsh to include material from the Arundel Formation (Lower Cretaceous) of Maryland, United States. Marsh recognized two species, P. nanus and P. altus. The former is well represented by a collection of mostly disarticulated elements, while the latter is known from only a tibia and some isolated vertebrae. Moreover, the presence of the genus Pleurocoelus was mentioned in Middle Cretaceous strata in the central north and central west of Texas (Comanche Series, Trinity Group). A reinterpretation of material previously assigned to Pleurocoelus suggests that (1) P. nanus corresponds to a valid species; (2) P. altus does not appear to correspond to an adult of P. nanus, as was proposed be various authors; and (3) sufficient evidence does not exist to demonstrate that the Comanchean species and the Maryland species correspond to the same genus (Pleurocoelus).
Pleurocoelus was traditionally included in the family Brachiosauridae, extending the biochron of this family of sauropods. In a numerical analysis of characters considered from the material previously assigned to Pleurocoelus, P. nanus is found to be the sister group to titanosaurs. These taxa share, among others, the following characters: absence of phalangeal articular surfaces on the distal metacarpals, and a transversely expanded distal tibia. Pleurocoelus retains anterior caudal vertebrae with flattened articular faces. “Pleurocoelus” altus exhibits an anteroposteriorly expanded distal tibia, a character which is plesiomorphic for sauropods.
The species represented in the Comanchean are probably basal members of the Titanosauria , as they present slightly procoelous anterior caudal vertebrae, dorsal vertebrae with the infradiapophyseal laminae bifurcated at their base, and the presence of a centro-parapophyseal lamina. Ichnological evidence supports the existence of basal titanosaurs in North America during the Middle Cretaceous.