FIG. 41 in The anatomy of Euphanerops longaevus Woodward, 1900, an anaspid-like jawless vertebrate from the Upper Devonian of Miguasha, Quebec, Canada

FIG. 41. — Euphanerops longaevus Woodward, 1900; Escuminac Formation, lower Frasnian (Upper Devonian), Miguasha, Quebec, Canada; two possible interpretations of the digestive tract in the visceral cavity:A, interpretation based on the larval lamprey, hagfish or even gnathostome models, assuming that the entrance to the oesophagus is situated at the posterior end of the branchial apparatus, and that the stomach and posterior intestine form loops inside the abdominal cavity; B, interpretation based on the adult lamprey model, assuming that the oesophagus, stomach and intestine (dark grey) are dorsal to the pharynx (light grey), and that the respiratory water was conveyed to the gill pouches through a median oesophagobranchial duct (black), passing between the right and left series of gill pouches, and numerous individual branchial ducts (white dots). Not to scale.