Loganelliidae

For Loganellidae, a family of trilobites, see Asaphida.

Loganelliids
Loganellia scotica (Fossil and model, Museum am Löwentor, Stuttgart)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Infraphylum:	Agnatha
Class:	†Thelodonti
Order:	†Thelodontiformes
Family:	†Loganelliidae Karatajūtė-Talimaa 1997
Synonyms
Loganiidae Karatajūtė-Talimaa 1978

Loganelliidae is an extinct family of thelodonts in the order Thelodontiformes.[1] They are distinguished by the star or cross shaped ridges located on their head scales.

Morphology

The head scales possess cross shaped or star shaped ridges, transitional scales are rhomboidal, and trunk scales are horizontally elongated. The crown is notably posteriorly pointed, with the apex extending beyond the base. The main crown surface is flat and smooth, and can be inclined in either horizontal direction. The base of the crown possesses a short spine which points downwards and anteriorly.[2][3]

Classification

The family contains the following genera:[4]

• †Angaralepis
• †Illoganellia
• †Larolepis
• †Loganellia
• †Nunavutia
• †Sandivia
• †Stroinolepis
• †Talimaalepis
• †Valyalepis

References

1. Wilson, M. V. H.; Märss, T. (2009). "Thelodont phylogeny revisited, with inclusion of key scale-based taxa". Estonian Journal of Earth Sciences. 58 (4): 297. doi:10.3176/earth.2009.4.08.
2. "Loganellia scotica, TRAQUAIR, 1898". The Fossil Forum. Retrieved 2021-10-03.
3. Märss, Tiiu (7 February 2006). "Theolodonts (Agnatha) from the basal beds of the Kuressaare Stage, Ludlow, Upper Silurian of Estonia" (PDF).
4. Ferrón, H. G.; Martínez-Pérez, C.; Turner, S.; Manzanares, E.; Botella, H. (2018). "Patterns of ecological diversification in thelodonts" (PDF). Palaeontology. 61 (2): 303–315. doi:10.1111/pala.12347.