Developmental growth patterns of the filter-feeder pterosaur, Pterodaustro guiñazui - PubMed (original) (raw)

Comparative Study

Developmental growth patterns of the filter-feeder pterosaur, Pterodaustro guiñazui

A Chinsamy et al. Biol Lett. 2008.

Abstract

Life-history parameters of pterosaurs such as growth and ontogenetic development represent an enigma. This aspect of pterosaur biology has remained perplexing because few pterosaur taxa are represented by complete ontogenetic series. Of these, Pterodaustro is unique in that besides being represented by hundreds of individuals with wing spans ranging from 0.3 to 2.5m, it includes an embryo within an egg. Here we present a comprehensive osteohistological assessment of multiple skeletal elements of a range of ontogenetic sizes of Pterodaustro, and we provide unparalleled insight into its growth dynamics. We show that, upon hatching, Pterodaustro juveniles grew rapidly for approximately 2 years until they reached approximately 53% of their mature body size, whereupon they attained sexual maturity. Thereafter, growth continued for at least another 3-4 years at comparatively slower rates until larger adult body sizes were attained. Our analysis further provides definitive evidence that Pterodaustro had a determinate growth strategy.

PubMed Disclaimer

Figures

Figure 1

Figure 1

Bone microstructure of Pterodaustro. (a) Transverse section of humerus MMP1207 showing the resorptive medullary surface (arrow). (b) Oblique section of humerus MMP1469 showing the well-developed layer of inner circumferential lamellar (arrow) bone that lines the medullary cavity (M). (c) Transverse section of tibia V28. Black arrows indicate periodic interruptions in growth. Note the close spacing of the outer three growth marks and the gradual decrease in the number of ‘blood vascular’ channels towards the periphery. The medullary cavity is lined by an inner circumferential layer of bone (white arrow). (d) Longitudinal section of the proximal end of femur V382 (largest known femur of Pterodaustro). A distinct layer of bone lines the ‘articular edge’ of the bone (arrow).

Figure 2

Figure 2

Schematic growth curve of Pterodaustro based on the analysis of the bone microstructure. It appears that early growth occurred rapidly for about 2 years until approximately 53% of adult size, when sexual maturity occurred. Thereafter, growth continued at a slower rate for 3–4 years until skeletal maturity was reached.

Similar articles

Cited by

References

    1. Bennett S.C. The ontogeny of Pteranodon and other pterosaurs. Paleobiology. 1993a;19:92–106.
    1. Bennett S.C. Year classes of pterosaurs from the Solnhofen limestone of southern Germany. J. Vert. Paleontol. 1993b;13:26A.
    1. Bennett S.C. A statistical study of Rhamphorhynchus from the Solnhofen limestone of Germany: year classes of a single large species. J. Paleontol. 1995;69:569–580.
    1. Castanet J, Vieillot H.F, Meunier J, De Ricqlès A. Bone and individual aging. In: Hall B.K, editor. Bone: bone growth. CRC Press; Boca Raton, FL: 1993. pp. 245–283.
    1. Chabreck R.H, Joanen T. Growth rates of American alligators in Louisiana. Herpetologica. 1979;35:51–57.

Publication types

MeSH terms

LinkOut - more resources