Prehistoric anthropogenically-mediated extinctions have impacted global biodiversity; however effects on herpetofauna are poorly-documented. New Zealand’s Diplodactylidae geckos exhibit high species-level diversity, largely independent of discernible osteological changes (cryptic). Consequently, taxonomic affinities of isolated skeletal elements (fossils) are primarily determined by relative size, particularly in the identification of Hoplodactylus duvaucelii; New Zealand’s largest extant gecko species. Here, three-dimensional geometric morphometrics of maxillae (a common fossilized element) was used to determine whether consistent shape and size differences exist between genera, and if cryptic extinctions have occurred in ‘Hoplodactylus cf. duvaucelii’. Sampling included 13 Diplodactylidae species from five genera, and 11 Holocene ‘H. cf. duvaucelii’ subfossil individuals. We found phylogenetic history was the most important predictor of maxilla morphology among extant Diplodactylidae genera. Relative size comparisons could only differentiate Hoplodactylus from other genera, with the remaining genera exhibiting variable degrees of overlap. Six subfossils were positively identified as H. duvaucelii, confirming their proposed Holocene distribution throughout New Zealand. Conversely, five subfossils showed no affinities towards any modern Diplodactylidae genera, implying either increased morphological diversity in mainland ‘H. cf. duvaucelii’ or the presence of at least one extinct, large, broad-toed Diplodactylidae species. These results highlight the impact of anthropogenic disturbances on insular reptile diversity.

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No competing interests reported.
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Posted 10 Feb, 2021
On 23 Feb, 2021
Received 14 Feb, 2021
On 08 Feb, 2021
Invitations sent on 08 Feb, 2021
On 08 Feb, 2021
On 08 Feb, 2021
On 05 Feb, 2021
On 05 Feb, 2021
Posted 10 Feb, 2021
On 23 Feb, 2021
Received 14 Feb, 2021
On 08 Feb, 2021
Invitations sent on 08 Feb, 2021
On 08 Feb, 2021
On 08 Feb, 2021
On 05 Feb, 2021
On 05 Feb, 2021
Prehistoric anthropogenically-mediated extinctions have impacted global biodiversity; however effects on herpetofauna are poorly-documented. New Zealand’s Diplodactylidae geckos exhibit high species-level diversity, largely independent of discernible osteological changes (cryptic). Consequently, taxonomic affinities of isolated skeletal elements (fossils) are primarily determined by relative size, particularly in the identification of Hoplodactylus duvaucelii; New Zealand’s largest extant gecko species. Here, three-dimensional geometric morphometrics of maxillae (a common fossilized element) was used to determine whether consistent shape and size differences exist between genera, and if cryptic extinctions have occurred in ‘Hoplodactylus cf. duvaucelii’. Sampling included 13 Diplodactylidae species from five genera, and 11 Holocene ‘H. cf. duvaucelii’ subfossil individuals. We found phylogenetic history was the most important predictor of maxilla morphology among extant Diplodactylidae genera. Relative size comparisons could only differentiate Hoplodactylus from other genera, with the remaining genera exhibiting variable degrees of overlap. Six subfossils were positively identified as H. duvaucelii, confirming their proposed Holocene distribution throughout New Zealand. Conversely, five subfossils showed no affinities towards any modern Diplodactylidae genera, implying either increased morphological diversity in mainland ‘H. cf. duvaucelii’ or the presence of at least one extinct, large, broad-toed Diplodactylidae species. These results highlight the impact of anthropogenic disturbances on insular reptile diversity.

Figure 1

Figure 2
No competing interests reported.
This is a list of supplementary files associated with this preprint. Click to download.
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