Adenoviruses are medium-sized DNA viruses with very high host fidelity. The phylogenetic relationships of the adenoviruses strongly resemble that of their hosts, consistent with evolutionary codivergence. The genus Atadenovirus appears to have evolved in squamate hosts. Perhaps the best known of the squamate adenoviruses is Agamid adenovirus 1 (AgAdV1), found most commonly in central bearded dragons (Pogona vitticeps), where it is a prevalent cause of hepatitis/enteritis, especially in young animals. All previous reports of adenoviruses in bearded dragons were AgAdV1. Helodermatid adenovirus 2 (HeAdV2) was first seen in Mexican beaded lizards (Heloderma horridus). Subsequently, partial adenoviral polymerase gene sequence from a western bearded dragon (Pogona minor) in Australia was found to share 99% nucleotide homology with HeAdV2. This article reports the discovery of a virus identical to HeAdV2 in a captive central bearded dragon in Florida and wild Gila monsters (Heloderma suspectum) in Arizona. Additionally, a partial adenoviral polymerase gene sharing 98% homology with this HeAdV2 was discovered in a death adder (Acanthophis antarcticus) in Australia. These findings call into question the provenance of HeAdV2. Further studies of atadenoviral host range, diversity of adenoviruses in captive animals, and characterization of adenoviruses from wild squamates are indicated.