Eight specimens representing four complete conodont animals have been recovered from Carboniferous sediments from central Montana. These specimens have conodont assemblages identified as Lochriea and Scottognathus. The conodont animal is 70 mm long and is bilaterally symmetrical from anterior to posterior. The anterior portion contains an oral opening, a dorsal nerve cord, and notostyle. The median section contains a gut (called the deltaenteron) and circulatory system (the ferrodiscus). The conodont assemblage is in the deltaenteron and is believed to have functioned as a food-filtering system. The posterior portion is marked by an anteroventral anal pore. Also, a rudder-fin is attached to the dorsal-posterior edge. The membrane covering the body was reticulate.
The conodont animal was a free-swimming form which went in search of its food.
The concept of assemblages, where more than one form-genus of conodont occurs in the body of one animal, is correct.
The presence of a postanal portion of the body, a rudder-fin, a dorsal nerve cord, a notostyle, a bilaterally symmetrical body, and a cell structure capable of producing calcium phosphate lead us to believe that the animal bearing conodonts was in the direct line as an ancestor to the vertebrates.