laboratorija

Livoniana: L. multidentata Ahlberg et al., 2000. Known only from 2 partial jaws.

Range: Middle or Late Devonian (Givetian or Frasnian) of the Baltics

Phylogeny: Elpistostegalia:: (Elginerpetonidae + ((Metaxygnathus + Ventastega) + Tetrapoda)) + *.

Characters: dentary very robust, expanding into club-shaped structure anteriorly; dentary-coronoid suture interdigitating anteriorly, straight posteriorly; dentary forms dorsal & anterior margins of symphysial Meckelian exposure; parasymphysial plate large & contacts dentary, prearticular & coronoid; prearticular forms posterior margin of symphysis; anterior coronoid narrow & without teeth; precoronoid fossa greatly reduced or absent; splenial without extensive medial lamina; splenial robust, with deeply-buried lateral line canal; splenial dentary suture invisible in lateral view; teeth with dentine folding pattern like tetrapods, with no side-branches or enclosed spaces; dentary with multiple (5-6) rows of teeth at anterior end; dentary teeth face dorsomedially; dentary fang pair within, not medial to, innermost tooth row; dentary fang pair only slightly larger than other teeth; dentary with 3 tooth rows posteriorly, additional rows being added buccally; dermal ornament lacks tetrapod "starburst" pattern.

Notes: [1] Ahlberg et al. note that the presence of the lateral & medial parasymphysial foramina (see figure) and the lack of Meckelian exposure between the prearticular & coronoid are "all diagnostic tetrapod features."