A new coelacanth from the Middle Devonian of Latvia

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Abstract
We describe a new species of coelacanth, Miguashaia grossi sp. nov., recognized from isolated cranial, shoulder girdle bones and scales from the Upper Givetian Gauja and Lode Formations of two Latvian localities. This coelacanth, together with comparisons with other Devonian coelacanths, allows a more precise description of the plesiomorphic condition of the lower jaw, shoulder girdle, and palate. These plesiomorphic conditions are as follows. The dentary is shallow throughout, the articular-retroarticular is deep posteriorly where it is developed as two processes—one for the symplectic articulation and the other demarcating the posteroventral angle of the jaw. In the shoulder girdle plesiomorphic attributes include the large triangular clavicle, a cleithrum which is directed anterodorsally and possibly a large and polygonal extracleithrum. In the palate the pterygoid shows a dorsal process of unknown function mid-way along the dorsal margin and this is also a plesiomorphic feature of coelacanths.