Baltoniodus parvidentatus (Segeeva, 1963) from the Mójcza Limestone.

Diagnoza

The anterior process of the ke elements usually long but undenticulated.

Synonims:

Falodus parvidentatus n. sp.; SERGEEVA, 1963; Prioniodus alatus HADDING; SPASSOV and TELLER,1963; Falodus sp.; SPASSOV and TELLER, 1963; Prioniodus sp. n.  LINDSTROM; SPASSOV and TELLER, 1963; Oepikodus smithensis LINDSTROM; SPASSOV and TELLER, 1963; Prioniodus navis LINDSTROM; SPASSOV and TELLER, 1963; Tetraprioniodus superbus (RHODES); SPASSOV and TELLER, 1963; Trapezognathus lindstroemi sp. n.; SPASSOVand TELLER, 1963; Tetraprioniodus sp. LINDSTROM; SPASSOV and TELLER,1963; Gothodus cf. costulatus LINDSTROM; BEDNARCZYK, 1971;  Oistodus brevibasis SERGEEVA; BEDNARCZYK, 1971;. Prioniodus alatus parvidentatus (SERGEEVA) ; DZIK, 1976; Prioniodus (Baltoniodus) praevariabilis norrandicus n. ssp.; LOFGREN, 1978; Baltoniodus norrlandicus LOFGREN; STOUGE and BAGNOLl, 1991; Baltoniodus clavatus n. sp; STOUGE and BAGNOLl,1991;  Baltoniodus medius (DZIK): RASMUSSEN, 1991

Porównanie

There is a profound ontogenetic transformation in the shape of the sp elements in the species, much more apparent than in other species of the genus. Juvenile elements are characterized by a much shorter inner process than in mature ones (which is actually a recapitulation of phylogeny in ontogeny) and by a weakly developed posterior expansion of the basal cavit y. Also the length of the anterior process is extremely variable character in the ke element. This was a subject of highly directional evolution resulting in a gradual disappearance of the distinction between the ke and hi element s. Because of the population variability it seems inpractical to recognize more chronospecies in the lin eage, and to split this particular segment into two unit s as proposed by STOUGE and BAGNOLI (1991; actually, they applied the vertical concept of chronos pecies).

Autekologia

Występowanie geograficzne

A few specimens of Baltoniodus found by Dr. Wieslaw BEDNARCZYK in the
limestone exposed in the Bukówka quarry seem to belong to an early form of B. navis. Although the most diagnostic ke elements are not present in his collection, this is strongly suggested by the appearance of the tr element. Its successor, B. parvidentatus, seems to occur in the limestone intercalations in the Bukówka Sandstone recovered by the Bukówka IG I borehole, as suggested by long processes in the sp elements, and remains abundant up to the discontinuity surface in the Mójcza
Limestone.

Zasięg czasowy

Materiały muzealne

Literatura

Dzik, J. 1994a Conodonts of the Mójcza Limestone. In: J. Dzik, E. Olempska, & A. Pisera. Ordovician carbonate platform of the Holy Cross Mountains. Palaeontologia Polonica 53, 43-128.