Evolution of North American Lizards

Abstract

Lizards are a diverse reptile group with an ancient and global evolutionary history. Fossil lizards first appeared in North America during the Mesozoic. Many lizard lineages have inhabited North America throughout geologic time, including several lineages that are extinct, others that no longer occur on the continent, and many groups that are still there today. Lizards are currently found in a diverse range of habitats and in regions across the continent, including islands and human‐modified habitats. The modern lizard biota of North America contains diverse biogeographic and phylogenetic components along with the evolution of many distinctive behaviours, morphologies, and ecologies, including the evolution of venom, repeated limb loss, and ecological specialisations. Some lizards have been introduced to North America from elsewhere in the world or the continent, posing a potential problem for native biodiversity. Key Concepts North America contains an astounding diversity of lizards both in the modern biota and through geologic time. Although many fossil lizards are documented, there is still a lot to learn from the fossil record. Historic extirpations and extinctions of lizards are known and conservation efforts are needed to preserve lizard biodiversity. Biogeographic scenarios of lizards in North America are often disputed but are informed by fossil and molecular evidence. North American lizards have a diverse set of behavioural, morphological and ecological characteristics.

A Palaeogene stem crotaphytid ( Aciprion formosum ) and the phylogenetic affinities of early fossil pleurodontan iguanians

“…Fossil lizards are poorly described from the Oligocene compared with the Eocene and the Neogene, although glyptosaurine anguids are still relatively abundant though not diverse (see [107,108]). Few fossil pleurodontans are published from the Oligocene of North or South America [40], although many have been collected (SG Scarpetta 2023, personal observation).…”

Phylogenomic Assessment of Biodiversity Using a Reference-Based Taxonomy: An Example With Horned Lizards (Phrynosoma)

“…If set at the appropriate phylogenetic scale, this threshold can reflect shared biogeographic history, which might also affect the rates at which populations transition to species (Mittelbach et al, 2007). In this study, we compared genetic diversity metrics among Phrynosoma; all species in the clade have similar life history characteristics (Sherbrooke, 2003) and speciated across the same general biogeographic arena (Scarpetta et al, 2020). However, if species vary in the rate at which reproductive isolation evolves (Rabosky and Matute, 2013;Campillo et al, 2020), lineages will acquire evolutionary independence at different rates, making it difficult to identify a fixed threshold.…”