Studies of Palaeozoic Thelodonti (Craniata: Agnatha).
Thelodus macintoshi Stetson 1928, the largest known thelodont (Agnatha: Thelodonti).
The subclass Thelodonti includes five orders, Loganelliiormes Turner, 1991, Shieliiormes Marss, Wilson & Thorsteinsson, 2002, Phlebolepidiformes Berg, 1937, Thelodontiformes Kiaer, 1932, and Furcacaudiformes Wilson & Caldwell, 1998.
The family Longodidae certainly belongs to the subclass Thelodonti as its squamation is built of separate dermal scales with a crown, neck, and base.
Class AGNATHA Cope, 1889 Subclass THELODONTI
Kiaer, 1932 INCERTI ORDINIS Family OESELIIDAE nov.
, Agnatha) from the Lower Silurian of North Greenland, with special reference on their stratigraphical and palaeogeographical significance.
With these revised interpretations, it will be possible for new reconstructions and artistic representations of Phlebolepis elegans to be based on more reliable information, so that it can continue to be used as a prime example of both Silurian vertebrates and members of the Thelodonti
. In addition, comparisons of the morphology of Phlebolepis with that of other early vertebrates will have a sounder basis, leading to improved understanding of the evolution of the vertebrate body plan, including the mouth and paired and median fins.
Articulated squamations as well as many isolated scales derived from acetic-acid residues of rock samples, allow establishment of 39 species (25 of which are new) of Thelodonti
, distributed in 25 genera (10 new) and 16 families (6 new), along with 5 orders (1 new), as well as two new species that are provisionally classified as chondrichthyans.
The lower part of the Viita Beds in the interval of 60.2-64.8 m contains an assemblage of the thelodonts Thelodonti
the same general type is found in two or more subclasses), but on the other hand, the finer details of the ultrasculpture are more specific and allow the subdivision, for example, of the subclass Thelodonti
, into four orders.
Our understanding of the Palaeozoic vertebrate subclass Thelodonti
has improved greatly in recent years as a result of new discoveries (e.g., Wilson & Caldwell 1993, 1998; Mdrss 1999; Mdrss et al.
, Heterostraci and Arthrodina from the Chortkov Stage of Podolia.