The evolutionary trend of platform denticulation in Middle Triassic acuminate Gondolellidae (Conodonta)

Abstract

Acuminate Middle-Late Triassic Gondolellidae are characterized by an ellipsoid platform with a central to posterior amygdaloid basal cavity and an octomembrate apparatus of gondolelloid affinity. Starting with a neospathodiform proteromorph during the Anisian, their anagenetic lineage developed during the Fassanian, Longobardian, and Julian, ending in another neospathodiform proteromorph. As the increase in complexity in the platform denticulation is an important evolutionary trend, three new genera are proposed: Guexispathodus n. gen., Marquezella n. gen., and Kirilella n. gen., which, together with Pseudofurnishius and Mosherella, represent the subfamily Marquezellinae n. subfam.

The Ladinian–Carnian conodont fauna at Yize, Yunnan, southwestern China, with implications for conodont palaeoecology and palaeogeography

“…2015; Plasencia et al . 2018). This evolutionary trend is not yet seen in South China and North America owing to the paucity of Budurovignathus elements.…”

“…A transition from smooth to nodose or denticulated platforms is first seen in the B. japonica -B. mungoensis -B. diebeli lineage and in B. mostleri (e.g. Balini et al 2000;Chen et al 2015;Plasencia et al 2018). This evolutionary trend is not yet seen in South China and North America owing to the paucity of Budurovignathus elements.…”

“…However, the FAD of B. diebeli is lower than the FAD of Daxatina canadensis, and B. diebeli is not widely distributed (e.g. Krystyn, 1983;Loriga et al 1998;Krystyn et al 2004;Mietto et al 2007Mietto et al , 2012Orchard, 2010;Plasencia et al 2018;Karádi et al 2022). Mosherella newpassensis is known in North America and South China but not in the western Tethys (Orchard, 2010).…”

Geology and accretionary age of the Otori Unit, North Kitakami Belt

“…According to ICZN Article 13.1.1 to 13.1.3, new names are required to be accompanied by a description or definition, or by bibliographic reference to such a statement, or to be proposed as a new replacement name. The third case applies to both Sephardiella (March et al, 1988) and Budurovignathus (Kozur, 1988), and thus both are available and have equal priority, contrary to the statements in Plasencia et al (2018). However, as Plasencia et al (2007) mentioned, Sudar (1989) selected Sephardiella as the first reviser six months prior to Kozur (1989) that preferred Budurovignathus, and the former is the valid name.…”

“…11B is rather poorly imaged and broken at the anterior, but the platform outline and posteriorly extended keel matches the characters of S. mungoensis. Plasencia et al (2007Plasencia et al ( , 2018 argued that the genus name Sephardiella proposed by March et al (1988) and described by March et al (1990) has priority over the more commonly used Budurovignathus, which was established without diagnosis or description by Kozur (1988). Both Sephardiella (March et al, 1988) and Budurovignathus (Kozur, 1988) were proposed as replacement names for Carinella Budurov.…”