Data from: Wear, tear and systematic repair: testing models of growth dynamics in conodonts with high-resolution imaging

Conodont elements are the earliest mineralised vertebrate dental tools and
the only ones capable of extensive repair. Two models of conodont growth,
as well as the presence of a larval stage, have been hypothesised. We
analysed normally and pathologically developed elements to test these
hypotheses and identified three ontogenetic stages characterised by
different anisometric growth and morphology. The distinction of these
stages is independently corroborated by differences in tissue strontium
content. The onset of the last stage is marked by the appearance of wear
resulting from mechanical food digestion. At least five episodes of damage
and repair could be identified in the normally developed specimen. In the
pathological element, function was compromised by development of abnormal
denticles. This development can be reconstructed as addition of new growth
centres out of the main growth axis during an episode of renewed growth.
Our findings support the model of periodic retraction of elements and
addition of new growth centres. Changes in strontium content coincident
with distinct morphology and lack of wear in the early life stage indicate
that conodonts might have assumed their mature feeding habit of predators
or scavengers after an initial larval stage characterised by a different
feeding mode.