A revision of European Plesiosminthus (Rodentia, Dipodidae), and new material from the upper Oligocene of Teruel (Spain)
Author
Freudenthal, Matthijs
Author
Martín-Suárez, Elvira
text
Palaeontologia Electronica
2017
2017-08-31
9
1
1
25
http://dx.doi.org/10.26879/678
journal article
10.26879/678
1094-8074
13344530
A085E4EE-97FA-4BB7-AE08-C1674AADAF40
the anteroloph in M1; antecingulum, a cingulum ridge at the base of the anteroloph in M1.
V' is the coefficient of variation (Range divided by median) as defined by
Freudenthal and Cuenca Bescós (1984)
.
Photographs were taken on the electron microscope FEI ESEM QUANTA 400 of the ‘Centro de Instrumentación Científica’ of the University of
Granada
.
Measurements were taken with a Wild M8 binocular microscope, equipped with a mechanical stage with electronic sensors, connected to a computer through a Sony Magnescale measuring unit. The measurement data were processed using a private computer program, written in Visual Basic. Measurements are given in mm.
Locality codes are explained in
Table 2
. Other abbreviations are: pcdha = protoconid hind arm; m1, m2, m3 = lower molars; M1, M2, M3 = upper molars.
For some characters morphology values (MV) have been calculated (see
Freudenthal, 2004
), using the equation
MV = Σ(n-1)
fn
/ (C-1)
Σfn
,
where C is the number of character states, and
fn
is the observed frequency for the nth character state. For example, if four character states are distinguished, the consecutive states score 0,
0.333
,
0.666
, and 1.0, respectively. The scores of all specimens are summed up, and the result is divided by the total number of specimens, leading to a value between 0 and 1. MV is typically useful for features, that in fact have a continuous size representation, e.g., for a length: absent/short /medium/ long, and is an approximation of actually measuring the parameter in each specimen, and calculating the mean of the measurements. It may be calculated on actual numbers of specimens, or on percentages; in the latter case
Σfn
= 100.