Dear collegues,
we're pleased to announce that a new publication on fetal and early
post-natal mineralization of timpanic bulla in fin whales is now
available in Plos One.
Cozzi B, Podestą M, Mazzariol S, Zotti A (2012) Fetal and
Early Post-Natal Mineralization of the Tympanic Bulla in Fin
Whales May Reveal a Hitherto Undiscovered Evolutionary Trait. PLoS
ONE 7(5): e37110. doi:10.1371/journal.pone.0037110
Abstract
The evolution of the cetacean skeleton followed a path
that differentiated this group from other terrestrial mammals
about 50 million years ago, and debate is still going on about the relationships
between Cetacea and Artiodactyla. Some skeletal traits of the basilosaurids (the more
advanced forms of Archaeocetes), such as the expansion of the
peribullary air sinuses, dental modification and vertebral size
uniformity are
maintained and further emphasized also in contemporary odontocetes
and mysticetes. Using Dual-Energy X-Ray Absorptiometry here we
report that the deposition of bone mineral in fetal and newborn
specimens of the fin whale Balaenoptera physalus is remarkably
higher in the bulla tympanica than in the
adjacent basal skull or in the rest of the skeleton. Ossification
of the tympanic bulla in fetal Artiodactyla (bovine, hippopotamus)
is minimal, becomes sensible after birth and then progresses
during growth, contrarily to the precocious mineralization that we
observed in fin whales. Given the importance of the ear bones for
the precise identification of phylogenetic relationship in therian
evolution, this feature may indicate a specific evolutionary trait
of fin whales and possibly other cetacean species or families.
Early mineralization of the tympanic bulla allows immediate sound
conduction in the aquatic medium and consequently holds potential
importance for mother-calf relationship and postnatal survival.
You can directly download and/or read the paper at the following
address:
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0037110
Best regards
Sandro Mazzariol
--
Dr. Sandro Mazzariol, DVM, PhD
Dipartimento di Biomedicina Comparata e Alimentazione (BCA)
Universitą degli Studi di Padova
AGRIPOLIS - Viale dell'Universitą, 16
35020 - Legnaro (PD)
tel.: +39 049 827 2963
fax: +39 049 827 2973
e-mail: sandro.mazzariol@unipd.it