Loganellia

{{Short description|Extinct genus of jawless fishes}}

{{Automatic taxobox

| fossil_range = {{fossil range|430|370}}

| image = Loganellia scotica fossil and model.jpg

| image_alt = Fossil and model of Loganellia scotica

| image_caption = Loganellia scotica (Fossil and model, Museum am Löwentor, Stuttgart)

| taxon = Loganellia

| authority = Fredholm, 1990

| synonyms =

| synonyms_ref =

| type_species = {{Extinct}}Loganellia scotica

| type_species_authority = (Traquair, 1898)

| subdivision_ranks = Species

| subdivision =

• {{extinct}}Loganellia aldridgei
• {{extinct}}Loganellia cuneata
• {{extinct}}Loganellia grossi
• {{extinct}}Loganellia matura
• {{extinct}}Loganellia prolata
• {{extinct}}Loganellia scotica
• {{extinct}}Loganellia sulcata
• {{extinct}}Loganellia unispinata

}}

Loganellia is a genus of jawless fish which lived between 430 and 370 million years ago, during the Silurian and Devonian periods of the Paleozoic.{{cite book|last1=Ungar|first1=Peter|title=Mammal Teeth: Origin, Evolution and Diversity|date=2010|publisher=Johns Hopkins University Press|location=Baltimore|page=77|isbn=9780801899515|url=https://books.google.com/books?id=BGGTYS2AgncC&q=%22Loganellia%22}} Loganellia belonged to the Thelodonti class and like other Thelodonts possessed scales instead of plate armor.

Loganellia are thought to be more closely related to the crown group of gnathostomes than conodonts. They are noted for their denticle whorls - oropharyngeal denticles that lined their branchial bars - which are thought to be homologous with other, later gnathostome teeth. In this sense, Loganellia may possess the earliest known dental structures related to modern teeth, and would have evolved in the throat, rather than through dermal denticles or jaws.

File:Loganellia scotica 432.JPG |File:Loganellia2.jpg |File:Fossil Thelodus Woodward.png