Gazelle : The Palestinian Biological Bulletin (ISSN 0178 – 6288) . Number 134, February 2016, pp. 1-44. | Page 24

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accessory denticles. P2 is the largest upper tooth and the first in the upper row
with large accessory denticles. Like the more posterior premolars, it is
buccolingually compressed and double-rooted. It has a dominant central
protocone flanked by denticles that decrease in size mesially and distally,
resulting in a tooth with a triangular profile. P3 is similar to but slightly smaller
than P2, except that it has a projection on the lingual side which is the remnant of
a third root. In P4, smaller than P2–3, the larger distal root is formed by the fusion
of two roots (Wikipedia).
The upper molars extend onto the zygomatic arch and are considerably smaller
than their neighbouring premolars. Like P4, their distal root is wider than the
mesial and formed by the fusion of two roots. The profiles of the molars are more
rounded than those of the premolars (Wikipedia).
Similar to the upper incisors, the lower incisors are simple conical teeth curved
distally and aligned with the cheek teeth. I1, the smallest tooth, is sitting on the
anterior-most portion of the dentary, with its alveolus left open towards the
mandibular symphysis and located as close to the alveolus of I2 as it can. I2, I3,
and C1 are very similar, considerably larger than I1 (Wikipedia).
The lower premolars are double-rooted, buccolingually compressed teeth, except
the deciduous P1 which is single-rooted. P3 is the second largest cheek tooth,
P4 the largest; both are very similar, dominated by the central cusp (Wikipedia).
In the lower molars the accessory denticles on the mesial edges are replaced by a
deep groove called the reentrant groove. The apical cusp is the primitive
protoconid. M2 and M3 are morphologically very similar. M3 is sitting high on the
ascending mandibular ramus (Wikipedia).

The Sign of Dorudon atrox Whale Fossil at Wadi El-Hitan (Whales Valley), Egypt.
Photo: Ola Mostafa Khalaf. 11.07.2012.
https://www.flickr.com/photos/50022881@N00/15292820287/
Gazelle : The Palestinian Biological Bulletin – Number 134 – February 2016