Sphenodraco (meaning "sphenodontian dragon") is an extinct genus of reptiles known from the Late Jurassic (Tithonian age) Altmühltal Formation, part of the Solnhofen Archipelago in Germany. The genus contains a Monotypic taxon, Sphenodraco scandentis, known from a nearly complete skeleton preserved on a slab and counterslab. The elongated proportions of its limbs are similar to those of living arboreal lizards. As such, Sphenodraco may be the first known fully tree-dwelling .
Discovery and naming
Sphenodraco is known from a single
Joint, nearly complete specimen preserved in ventral view (seen from the bottom) on two separate slabs (a part and counterpart). It was discovered in outcrops of the Altmühltal Formation (likely the Upper Eichstätt Member) near Eichstätt, Germany. Surprisingly—and for unknown reasons—these two slabs are housed separately in different institutions. The main slab, accessioned at the Naturmuseum Senckenberg in Germany as specimen SMF R414, comprises a
natural mold of the skeleton with some of the bone. It was first figured in 1931 and later reported in 1963 as belonging to the species
Homoeosaurus maximiliani.
The counterslab, housed at the Natural History Museum in London, England, as specimen NHMUK PV R 2741, contains most of the skeletal material. This part of the specimen had not been previously reported or described. In 2022, the counterslab was 'rediscovered' and identified as belonging to the same individual as SMF R414.
In a 2025 Academic paper, Victor Beccari and colleagues recognized several anatomical characters distinguishing these specimens from Homoeosaurus. As such, they described Sphenodraco scandentis as a new genus and species of rhynchocephalians based on these fossil remains. The Genus, Sphenodraco, combines the prefix spheno-—derived from the Ancient Greek σφήν ( sphḗn), meaning "wedge"
Classification
In their phylogenetic analyses (most parsimonious tree, implied weighting), Beccari and colleagues (2025) recovered
Sphenodraco as a member of the rhynchocephalian clade
Neosphenodontia, as the
sister taxon to
Kallimodon spp. in a clade also including
Homoeosaurus spp. These results are displayed in the simplified
cladogram below:
See also
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2025 in reptile paleontology
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Paleobiota of the Solnhofen Limestone
