DME {MASSTIMATE}

Developmental Mass Extrapolation

Description

This function estimates the body mass of an immature specimen based on the mass of a presumed adult and a standard measurement (e.g., femur length or circumference), as described by Erickson and Tumanova (2000).

Usage

DME(juv_proxy, adu_proxy, adu_mass, scale_fac = 3)

Arguments

juv_proxy

numeric value or vector corresponding to the measurement taken on the immature specimen(s) of interest

adu_proxy

numeric value corresponding to the measurement taken on the presumed adult representative

adu_mass

numeric value corresponding to the body mass of the adult representative

scale_fac

numeric value corresponding to the growth allometric scaling factor applied to the immature and adult specimens, defaults to 3 (i.e., isometry)

Details

It cannot be assumed that growth-related allometric scaling coefficients will be consistent with those derived from interspecific relationships of adults (e.g.,QE). DME was developed by Erickson and Tumanova (2000) in order to extrapolate the body mass of an adult to that of an immature specimen through the use of a growth-related scaling factor. Although the assumed scaling factor is that of isometry between a linear and volumetric measurement (scale_fac = 3), if an alternate scaling factor is known, then it can be incorporated by adjusting the scale_fac value.

Value

A numeric value or vector representing the mass estimate(s) in grams of the immature specimen(s).

Author(s)

Nicolas E. Campione

References

Brassey C. A., Maidment, S. C. R. & Barrett, P. M. (2015). Body mass estimates of an exceptionally complete Stegosaurus (Ornithischia: Thyreophora): comparing volumetric and linear bivariate mass estimation methods. Biology Letters, 11, 20140984.

Erickson G. M. and Tumanova, T. A. (2000). Growth curve of Psittacosaurus mongoliensis Orborn (Ceratopsia; Psittacosauridae) inferred from long bone histology. Zoological Journal of the Linnean Society, 130, 551-566.

See Also

QE cQE

Examples

##Based on the immature Stegosaurus from Brassey et al. (2015)

## Immature (NHMUK R36730: HC = 282, FC = 339, FL = 863
## Adult (YPM1853): HC = 352, FC = 425, FL = 1348

##DME estimate, adult extracted from dinos dataset
DME(juv_proxy = 863, adu_proxy = 1348, adu_mass = QE(352+425)[2])