X-ray microcomputed tomography reveals putative trematode metacercaria in a 100 million year-old lizard (Squamata: Agamidae)

A Brief Review of Lizard Inclusions in Amber

“…Furthermore, it was also concluded that the paraphalange, an accessory structure of toe pads, is not necessary for the adhesion mechanism based on qualitative and quantitative similarities between this specimen and both scansorial and non-scansorial squamata, and the fact that pad bearing and padless geckos have paraphalanges in common (Fontanarrosa et al, 2018). Poinar et al (2017) described trematode cysts in a fossilized lizard (F28461 BUICJW) included in new Burmese amber from the Noije Bum 2001 Summit Site mine. The metacercariae (encysted late stage larvae of a trematode) were located in cysts at the base of the femora.…”

“…The lizard specimen is characterized by a long tail, vestigial claws, longer fourth digits on the manus and pes and a unique shape of the lateral scales. All of these features fit the characteristics of Agamidae (Witten 1989;Hutchinson et al, 2012;Daza et al, 2016;Poinar et al, 2017). Due to the head and neck missing the body length was estimated only to measure 85-92 mm within a range of adult agamids (Manthey & Schuster, 1996).…”

“…However, as the specimen in question was incomplete it was not described in detail nor analyzed phylogenetically. In addition, it revealed that lizards were among intermediate hosts (the larva's host) of trematodes about 100 million years ago (Poinar et al, 2017). Daza et al (2018) named a specimen in a private collection (Federico Barlocher collection 8, SVL ≈ 19.1 mm) as Barlochersaurus winhtini, which was from the same mine in Kachin and had nine features to identify as Squamata as well as six to identify as Anguimorpha.…”

A Brief Review of Lizard Inclusions in Amber

“…The lizard specimen is characterized by a long tail, vestigial claws, longer fourth digits on the manus and pes and a unique shape of the lateral scales. All of these features fit the characteristics of Agamidae (Witten 1989;Hutchinson et al, 2012;Daza et al, 2016;Poinar et al, 2017). Due to the head and neck missing the body length was estimated only to measure 85-92 mm within a range of adult agamids (Manthey & Schuster, 1996).…”

“…However, as the specimen in question was incomplete it was not described in detail nor analyzed phylogenetically. In addition, it revealed that lizards were among intermediate hosts (the larva's host) of trematodes about 100 million years ago (Poinar et al, 2017 (Estes et al, 1988); ( 2) inwardly curved tooth crown (Rieppel, 1994); ( 3) clearly constricted outer margin of the frontal; (4) backwards elongated external nostril; (5) the absence of nodules on the internal surface of the retroarticular process (Conrad, 2008); ( 6) about 20 maxillary tooth loci (Rieppel, 1980a). Based on the above characteristics, Daza et al (2018) finally assigned the specimen to the stem Anguimorpha.…”