Report

Precocity in a tiny titanosaur from the Cretaceous of Madagascar

See allHide authors and affiliations

Science  22 Apr 2016:
Vol. 352, Issue 6284, pp. 450-453
DOI: 10.1126/science.aaf1509
  • Fig. 1 Perinate Rapetosaurus krausei (UA 9998).

    (A) Isometric growth of limb elements illustrated by four femora throughout ontogeny. Gray silhouette represents hatchling, color represents UA 9998. Orange outline is UA 9998, black is largest known Rapetosaurus (length = 143 cm), green and blue are intermediate Rapetosaurus femora (35) (figs. S2 and S3 and tables S1 to S3). (B) Right humerus, metacarpal III. (C) Right femur, fibula, metatarsal I, phalanx I.1, left tibia (reversed) in anterior view. High-resolution images archived at MorphoBank (Project 2326). (D) Proximal tibia epiphyseal microstructure. (E) Mid-diaphyseal tibia microstructure; arrow indicates hatching line. Scale bars: 20 cm (A), 3 cm (B and C), 500 μm [(D), inset], and 1 mm (D and E).

  • Fig. 2 Tibia mid-diaphyseal histology.

    (A) Histologic (left) and XRCT sections (right). Boxed areas are enlarged in (B) to (E). (B) Transition between embryonic (bottom left) and postnatal bone tissue (upper right); asterisk indicates the same location in (B) and (C). (C) Black bars bound hatching line zone, with decreased vascular canal dimensions. (D) Midcortex secondary remodeling in cross-polarized light. (E) Periosteal primary fibrolamellar bone. Scale bars: 1 cm (A), 500 μm (B), 300 μm (C and D), and 100 μm (E).

  • Fig. 3 Longitudinal and transverse XRCT sections.

    (A) Right femur; (B) left tibia; (C) right fibula; (D) left fibula; (E) right humerus; (F) left humerus; (G) right metatarsal I; (H) right metacarpal III. Arrows indicate hatching line. Scale bar: 1 cm.

  • Fig. 4 Tibia epiphyseal histology.

    (A) Proximal (top) and distal sections (bottom). Boxed areas are enlarged in (B) and (C). (B) Proximal calcified hypertrophic cartilage (CHC). (C) Distal CHC. (D) Metaphyseal region of the distal tibia illustrating stout, sharp metaphyseal CHC. (E) Proximal metaphysis preserves CHC “islands” within bony trabeculae. Scale bars: 1 cm (A), 500 μm (B and C), 300 μm (D), and 100 μm (E).

Supplementary Materials

  • Precocity in a tiny titanosaur from the Cretaceous of Madagascar

    Kristina Curry Rogers, Megan Whitney, Michael D’Emic, Brian Bagley

    Materials/Methods, Supplementary Text, Tables, Figures, and/or References

    Download Supplement
    • Materials and Methods
    • Supplementary Text
    • Figs. S1 to S4
    • Tables S1 to S5
    • References (3175)

Navigate This Article