Eggs of titanosaurid sauropods from the Upper Cretaceous of Auca Mahuevo (Argentina)
2004/08/01 by Gerald Grellet-Tinner, Gerald Grellet‐Tinner, Luis M Chiappe +3 · 17 citations
Earth and Planetary Sciences · Environmental Science · #Paleontology and Evolutionary Biology #Ichthyology and Marine Biology #Evolution and Paleontology Studies
paper · doi:10.1139/e04-049
Abstract
We provide a detailed description of the sauropod eggs from the Late Cretaceous nesting site of Auca Mahuevo (Neuquén Province, Argentina), the only eggs that are unequivocally associated with titanosaurid dinosaurs. These eggs are subspherical averaging 132 by 115 mm. Well-preserved specimens display a pronounced eggshell ornamentation that consists mostly of single nodes averaging 0.58 mm in diameter and 0.28 mm in height (base to apex) with internodular values of 0.52 to 0.87 mm. The pore canal network consists of vertical and horizontal canals intersecting at the bases of eggshell units. Vertical canals may fork defining a "Y" pattern and their diameters vary between 0.08 and 0.2 mm. Their surficial apertures of 0.15 to 0.29 mm are funnel like and located between the surficial nodes. In pristine specimens, the eggshell thickness equals 1.31 mm, and radial sections exhibit a single structural horizontal layer composed of juxtaposed shell units consisting of acicular calcite crystals radiating from an organic core. Relying only on taxonomically identified oological material, we regard this character also shared in the innermost layer (layer 1) of Deinonychus antirrhopus, oviraptorid theropods, and observed during an early oogenetic stage in extant bird as primitive for saurischians. The eggshell morphology advocates that these eggs were likely incubated in moist nesting environments, perhaps such as nests covered with vegetal matter. Examination of the South American megaloolithid eggshells reveals that the titanosaurid eggs from Auca Mahuevo are mostly similar to those described as Megaloolithus patagonicus and Megaloolithus pseudomamillare.
Citations
Cited by
- Embryonic skin from Late Cretaceous Sauropods (Dinosauria) of Auca Mahuevo, Patagonia, Argentina
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- A new Upper Cretaceous titanosaur nesting site from La Rioja (NW Argentina), with implications for titanosaur nesting strategies
- Preservation of Membrana Testacea in titanosaurid dinosaur eggshells from the Upper Cretaceous Deccan volcano-sedimentary strata of Central India
- Comparison of water vapor conductance in a titanosaur egg from the Upper Cretaceous of Argentina and a Megaloolithus siruguei egg from Spain
- Upper Cretaceous dinosaur nesting sites of Río Negro (Salitral Ojo de Agua and Salinas de Trapalcó-Salitral de Santa Rosa), northern Patagonia, Argentina
- The Auca Mahuevo nesting site (Upper Cretaceous, Argentina), revisited: new insights into the structural diversity and incubation mode of titanosaur (Dinosauria, Sauropoda) eggs
- Parataxonomic review of the Upper Cretaceous dinosaur eggshells belonging to the oofamily Megaloolithidae from India and Argentina
- The ‘Tuştea puzzle’ revisited: Late Cretaceous (Maastrichtian) Megaloolithus eggs associated with Telmatosaurus hatchlings in the Haţeg Basin
- Unusually thick dinosaur eggshell fragments from the Spanish Late Cretaceous
- What do giant titanosaur dinosaurs and modern Australasian megapodes have in common? [europepmc]
- Micro-CT scan reveals an unexpected high-volume and interconnected pore network in a Cretaceous Sanagasta dinosaur eggshell. [europepmc]
- Eggshell structure in Caiman latirostris eggs improves embryo survival during nest inundation. [europepmc]
- Biomechanical evidence suggests extensive eggshell thinning during incubation in the Sanagasta titanosaur dinosaurs. [europepmc]
- Cracking the egg: the use of modern and fossil eggs for ecological, environmental and biological interpretation. [europepmc]
- Two Late Cretaceous sauropods reveal titanosaurian dispersal across South America. [europepmc]
- Unexpected morphological variability in the eggshells of the South American caimans Caiman latirostris and Caiman yacare. [europepmc]
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