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© 2014 International Society of Zoological Sciences, Institute of Zoology/
Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd
Integrative Zoology 2015; 10: 227–229 doi: 10.1111/1749-4877. 12117
LETTER TO THE EDITOR
On the relationship between hypsodonty and longevity in
Myotragus balearicus–A comment on van der Geer (2014)
Xavier JORDANA,
1
Daniel DeMIGUEL
1
and Meike KÖHLER
2,3
1
Catalan Institute of Paleontology Miquel Crusafont, Autonomus University of Barcelona, Barcelona, Spain,
2
Catalan Institution
for Research and Advanced Studies (ICREA) at Catalan Institute of Paleontology Miquel Crusafont, Autonomus University of
Barcelona, Barcelona, Spain and
3
Department of Ecology, University of Barcelona, Barcelona, Spain
Correspondence: Xavier Jordana, Catalan Institute of
Paleontology Miquel Crusafont (ICP), ICTA-ICP Ediici Z c/
de les Columnes, s/n. Autonomus University of Barcelona,
08193 Cerdanyola del Vallès, Barcelona, Spain.
Email: xavier.jordana@icp.cat
In a recent paper published in a special issue of Inte-
grative Zoology on ‘Paleontology and evolution–part I.’
(Palombo 2014), the author (van der Geer 2014) takes
a review of the derived traits observed in endemic fos-
sil insular mammals, including body size variation,
cranial and postcranial changes, and modifications in
dentition. At one point in the discussion, the author mis-
interprets and seriously distorts statements by Jordana et
al. (2012) on the relationship between hypsodonty and
longevity in the fossil insular bovid Myotragus baleari-
cus Bate, 1909. Because van der Geer (2014) is intend-
ed as a comprehensive overview on general patterns and
the adaptive value of derived traits in lineages of insular
mammals, a clariication of these misunderstandings is
absolutely necessary.
On page 176, van der Geer writes “Jordana et al.
(2012) go a step further and maintain that the coexis-
tence of hypsodonty and longevity in M. balearicus
is entirely interlinked and of a causal nature, with diet
playing no role at all.” However, in Jordana et al. (2012)
we clearly contend that both factors in tandem (i.e. feed-
ing habits [diet] and longevity) were the likely forces
triggering the increase in molar hypsodonty in the evo-
lutionary lineage of Myotragus. For instance, we literal-
ly wrote the following: “feeding habits are not the sole
driving force behind increased crown height” (p. 3339);
“though high tooth wear could be among the causes un-
derlying an increase in molar crown height, this alone
is not enough to explain the outstanding hypsodonty in
M. balearicus” (p. 3343); “the feeding habits hypothe-
sis alone cannot explain the evolution of hypsodonty in
M. balearicus” (p. 3343); and “Our estimates on the lev-
el of dental abrasion in a highly hypsodont fossil insular
bovid exclude increased tooth height as a mere adapta-
tion to an enlarged range of the dietary niche as hitherto
suggested” (p. 3344).
Indeed, we even conducted a dental mesowear anal-
ysis to quantify the abrasiveness of the items (not only
food, but also exogenous particles such as dust and grit)
(DeMiguel et al. 2010) eaten by M. balearicus and con-
clude that it fed on a larger amount of abrasive material
than typical browsers. We suggest that this might indi-
cate that Myotragus tended “to signiicantly enlarge the
range of consumable plants and parts of plants such as
roots, thus ingesting large amounts of soil, in response
to resource limitation” (p. 3342). This contradicts the
suggestion of van der Geer (2014) that increased soil
particle intake was not considered in our study as an im-
portant factor explaining hypsodonty in insular taxa.
Our study further showed that the wear signature in
the diet of M. balearicus was significantly lower than