[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Missing data estimation in tyrannosaurid dinosaurs

Ben Creisler

A new paper:

Gavin J. Bradley, Michael E. Burns & Philip J. Currie (2015)
Missing data estimation in tyrannosaurid dinosaurs: Can diameter take
the place of circumference?
Cretaceous Research 55: 200-209

Missing data, due to taphonomic deformation, inaccessibility of
specimens, or human error in collecting, cataloguing and measuring
features, is a formidable problem in current palaeontological studies.
Missing values within a data set can undermine confidence in analyses,
skew results in promoting analyses of small portions of a population,
not necessarily representative of the entire data set, and drastically
decrease sample sizes. Missing data estimation methods, however, may
reduce the effects of these missing values and potentially boost
sample sizes for palaeontological studies. Here, six missing data
estimation models for the prediction of femoral circumferences in
tyrannosaurids were statistically tested and their predictive success
measured against true circumferences, and other models. The
statistical analyses suggest that estimation models based on
anteroposterior diameter values of tyrannosaurid femora were poor
predictors of circumference, whereas those based on mediolateral
diameters were much more successful. Three out of the six models, were
presented as viable alternatives to missing measured circumferences
and may be used to boost tyrannosaurid samples with significant levels
of missing data.