[D] Rapetosaurus krausei [Su] [sG] [T]
Describer
Curry-Rogers and Forster, 2001
Time
Cretaceous Late Maastrichtian
Classification
Saurischia Sauropodomorpha Sauropoda Titanosauria
Diet
Herbivore
Fossilsite
Anembalemba Member of Gres de Maevarano, Madagascar
Length
8 meters
Info
Genera - Skull - Typespecies
A nearly complete juvenile skeleton and two nearly complete skulls
A summary of the basic facts by Mickey Mortimer
Etymology
\\\\\\\\\\\\\\\"David Krause\\\\\\\\\\\\\\\'s giant lizard\\\\\\\\\\\\\\\", after Rapeto, a mischevious giant in Malagasy folklore.
Holotype
(UA 8698) maxillae, nasals, lacrimal, jugal, quadrate, pterygoids, partial basioccipital, paroccipital process, dentary, surangular, angular, twenty-four teeth
Referred
(FMNH PR 2184-2192, 2194, 2196, 2197, 2210) exoccipital, opisthotic, laterosphenoid, supraoccipital, frontals, prefrontals, surangular, parietal, squamosal, mid-caudal centrum (FMNH PR 2209) (juvenile) 75% complete skeleton (UCB 92829) mid-caudal centrum
Diagnosis
Expanded antorbital fenestra extends over tooth row; preantorbital fenestra positioned posterior to antorbital fenestra; subnarial foramen anteriorly positioned and dorsoventrally elongate; jugal process of maxilla posterodorsally elongate and narrow; frontals with median dome; quadrate with V-shaped quadratojugal articulation; supraoccipital with two anteriorly directed median parietal processes; pterygoid with extremely shallow basipterygoid articulation and dorsoventrally expanded anterior process; basipterygoid processes diverge only at distal extremes; dentary with 11 alveoli that extend two-thirds the length of the element; gracile cylindrical teeth with high-angle planar wear facets; 16 cervical vertebrae with constricted neural canals and continuous pre- and postspinal coels devoid of pre- or postspinal laminae; cervicalneural spines with proximal bifurcation and three pneumatized coels bounded by discrete laminae; 11 dorsal vertebrae with deep lateral pleurocoels; dorsal neural spines with strong pre- and postspinal laminae in deeply excavated anterior and posterior coels; dorsals with median interpre- and interpostzygapophyseal laminae; middle and posterior dorsals with divided spinodiapophyseal lamina; six sacral centra with deep lateral pleurocoels; all caudal centra procoelous with convex ventral margin lacking excavation; anterior caudal centra broad transversely and anteroposteriorly compressed; middle-posterior caudal centra with constant length:width ratio; anterior-middle caudal neural spines with spinoprezygapophyseal, prespinal and postspinal laminae on rectangular and anteriorly positioned neural arches; chevrons throughout 80% of tail; iliac peduncle of ischium comprises one-quarter of acetabulum; ischial peduncle of ilium low and poorly developed; pubis more than twice as long as ischium; scapula and coracoid with equal glenoid contribution; scapular blade not distally expanded; humerus/femur length quotient 0.80; radius and ulna with oblique interosseus ridges.
Curry Rogers, K and Forster, C. (2004) The skull of Rapetosaurus krausei (Sauropoda: Titanosauria) from the Late Cretaceous of Madagascar. JVP 24(1): 121-144.
Abstract
Rapetosaurus krausei (Sauropoda: Titanosauria) from the Upper Cretaceous Maevarano Formation of Madagascar is the best-preserved and most complete titanosaur yet described.
The skull of Rapetosaurus is particularly significant because most titanosaurs are diagnosed solely on the basis of fragmentary postcranial material, and knowledge of the titanosaur skull has remained incomplete. Material referred to Rapetosaurus includes the type skull from an adult that preserves the basicranium, rostrum, mandible, and palate.
A second, juvenile skull preserves most of the braincase and cranial vault, as well as some of the palate and lower jaw. Here we provide a detailed description of Rapetosaurus cranial anatomy and highlight comparative relationships among known titanosaur and other neosauropod skulls.
The Rapetosaurus skull is similar to those of diplodocoids in its overall shape, with retracted external nares and an elongated snout. However, extensive tooth distribution and bone articulations surrounding the external narial region and orbit are more similar to those of macronarians like Camarasaurus and Brachiosaurus.
The maxilla, basicranium, paroccipital process, and pterygoid are among the most diagnostic elements of the Rapetosaurus skull, along with the enlarged antorbital fenestra, anteroventrally oriented braincase, and mandible. Titanosaur crania exhibit a greater diversity than previously recognized and, in light of Rapetosaurus, it is apparent that there is not a narrowly constrained bauplan for the skull of titanosaurs. Broad generalizations about evolution based on previously known, fragmentary fossils require re-evaluation. Ultimately, Rapetosaurus will be key in resolving titanosaur higher-level and ingroup phylogeny.
Curry-Rogers and Forster, 2001
Time
Cretaceous Late Maastrichtian
Classification
Saurischia Sauropodomorpha Sauropoda Titanosauria
Diet
Herbivore
Fossilsite
Anembalemba Member of Gres de Maevarano, Madagascar
Length
8 meters
Info
Genera - Skull - Typespecies
A nearly complete juvenile skeleton and two nearly complete skulls
A summary of the basic facts by Mickey Mortimer
Etymology
\\\\\\\\\\\\\\\"David Krause\\\\\\\\\\\\\\\'s giant lizard\\\\\\\\\\\\\\\", after Rapeto, a mischevious giant in Malagasy folklore.
Holotype
(UA 8698) maxillae, nasals, lacrimal, jugal, quadrate, pterygoids, partial basioccipital, paroccipital process, dentary, surangular, angular, twenty-four teeth
Referred
(FMNH PR 2184-2192, 2194, 2196, 2197, 2210) exoccipital, opisthotic, laterosphenoid, supraoccipital, frontals, prefrontals, surangular, parietal, squamosal, mid-caudal centrum (FMNH PR 2209) (juvenile) 75% complete skeleton (UCB 92829) mid-caudal centrum
Diagnosis
Expanded antorbital fenestra extends over tooth row; preantorbital fenestra positioned posterior to antorbital fenestra; subnarial foramen anteriorly positioned and dorsoventrally elongate; jugal process of maxilla posterodorsally elongate and narrow; frontals with median dome; quadrate with V-shaped quadratojugal articulation; supraoccipital with two anteriorly directed median parietal processes; pterygoid with extremely shallow basipterygoid articulation and dorsoventrally expanded anterior process; basipterygoid processes diverge only at distal extremes; dentary with 11 alveoli that extend two-thirds the length of the element; gracile cylindrical teeth with high-angle planar wear facets; 16 cervical vertebrae with constricted neural canals and continuous pre- and postspinal coels devoid of pre- or postspinal laminae; cervicalneural spines with proximal bifurcation and three pneumatized coels bounded by discrete laminae; 11 dorsal vertebrae with deep lateral pleurocoels; dorsal neural spines with strong pre- and postspinal laminae in deeply excavated anterior and posterior coels; dorsals with median interpre- and interpostzygapophyseal laminae; middle and posterior dorsals with divided spinodiapophyseal lamina; six sacral centra with deep lateral pleurocoels; all caudal centra procoelous with convex ventral margin lacking excavation; anterior caudal centra broad transversely and anteroposteriorly compressed; middle-posterior caudal centra with constant length:width ratio; anterior-middle caudal neural spines with spinoprezygapophyseal, prespinal and postspinal laminae on rectangular and anteriorly positioned neural arches; chevrons throughout 80% of tail; iliac peduncle of ischium comprises one-quarter of acetabulum; ischial peduncle of ilium low and poorly developed; pubis more than twice as long as ischium; scapula and coracoid with equal glenoid contribution; scapular blade not distally expanded; humerus/femur length quotient 0.80; radius and ulna with oblique interosseus ridges.
Curry Rogers, K and Forster, C. (2004) The skull of Rapetosaurus krausei (Sauropoda: Titanosauria) from the Late Cretaceous of Madagascar. JVP 24(1): 121-144.
Abstract
Rapetosaurus krausei (Sauropoda: Titanosauria) from the Upper Cretaceous Maevarano Formation of Madagascar is the best-preserved and most complete titanosaur yet described.
The skull of Rapetosaurus is particularly significant because most titanosaurs are diagnosed solely on the basis of fragmentary postcranial material, and knowledge of the titanosaur skull has remained incomplete. Material referred to Rapetosaurus includes the type skull from an adult that preserves the basicranium, rostrum, mandible, and palate.
A second, juvenile skull preserves most of the braincase and cranial vault, as well as some of the palate and lower jaw. Here we provide a detailed description of Rapetosaurus cranial anatomy and highlight comparative relationships among known titanosaur and other neosauropod skulls.
The Rapetosaurus skull is similar to those of diplodocoids in its overall shape, with retracted external nares and an elongated snout. However, extensive tooth distribution and bone articulations surrounding the external narial region and orbit are more similar to those of macronarians like Camarasaurus and Brachiosaurus.
The maxilla, basicranium, paroccipital process, and pterygoid are among the most diagnostic elements of the Rapetosaurus skull, along with the enlarged antorbital fenestra, anteroventrally oriented braincase, and mandible. Titanosaur crania exhibit a greater diversity than previously recognized and, in light of Rapetosaurus, it is apparent that there is not a narrowly constrained bauplan for the skull of titanosaurs. Broad generalizations about evolution based on previously known, fragmentary fossils require re-evaluation. Ultimately, Rapetosaurus will be key in resolving titanosaur higher-level and ingroup phylogeny.