Birds of the IDU (Summary)

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Birds of the IDU (Summary)

Post by Bears Armed » Fri Feb 21, 2020 7:43 pm

Overview

Introduction

Birds – Those of the vertebrate animals that are members of the Class ‘Aves’, distinguished from the other types of ‘Tetrapods’ (literally the “Four-footed”; those others are the Amphibians, Reptiles, and Mammals) by their possession of feathers, according to traditional taxonomic reckoning. An offshoot of the Dinosaurs, whose continued designation as a ‘Class’ is awkward because the Dinosaurs are generally defined as only a ‘Super-Order’ (which is a lower taxonomic rank…) within the class ‘Reptilia’, and whose earliest members’ differentiation from feathered “Non-Avian Dinosaurs” is hard to define, according to more current thinking.
As this thread will deal primarily with the IDU’s birds from the geological era after the extinction of the “Non-Avian Dinosaurs” I won’t really need to differentiate between these two groups here, and continuing to classify Aves as a ‘Class’ makes applying labels systematically to its various subdivisions easier, so that’s what I’m going to do.

This thread will simply list & explain the sub-divisions of the Birds down to the level of ‘Family’ — or possibly, in some cases, ‘Sub-Family’ — and state which of the IDU’s continents each of those groups is (or, at least, “was”…) found on & around: Further detail will be given in threads about the relevant continents, instead.

Basic Evolution and Taxonomy of the Birds
The earliest “birds”, such as the famous Archaeopteryx, were anatomically just feathered Dinosaurs whose forelimbs had developed into wings… and may have been only one group among several of Dinosaurs for which this was the case. They had long tails in which the vertebral column extended almost to the tip, had long jawbones with teeth rather than just [lighter-weight] beaks, had claws on their fingers, and did not have their breastbones expanded into ‘keels’ as anchors for efficient flight-muscles.
(Indeed, gaps in the fossil record mean that we cannot even be certain that Archaeopteryx was in the line of descent that led to modern Birds rather than just a less closely related side-shoot of the evolutionary tree…)

These ‘basal’ forms gave rise to two main groups, the ‘Enantionithes’ ( = “Opposite Birds”, so-called because of a significant detail in their shoulder joints) and the ‘Euornithes’ ( = “Good Birds”, i.e “True Birds”, the stock from within which the ancestors of all of today’s birds arose). Lineges within both of these branches evolved ‘pygostyle’-type tails (in which just a few vertebra persist, generally fused together in most modern birds, forming a short structure that supports a longer tail which consists solely of feathers) of various forms: they also developed more ‘keel’-like breastbones (presumably with improved flight-muscles attached), lost their finger-claws, and lost teeth in favour of beaks, to varying extents… but these changes happened at differing rates in different lines, so that groups showing quite significant differences in these respects frequently co-existed. Fossil evidence uncovered in recent decades currently suggests that on RL Earth it was the ‘Enantiornithes’ that dominated during the Mesozoic Era (‘Age of Dinosaurs’), at least on land: The best-known Mesozoic groups of ‘Euronithes’ were apparently seabirds, in the orders ‘Icthyornithiformes’ (the genus Ichthyornis contained “gull-sized” flyers with teeth) and ‘Hesperornithiformes’ (the genus Hesperornis was a larger, flightless, foot-propelled diver, also with teeth), although fossils of more land-based types have also been uncovered in recent decades.

All of the birds alive in modern times are classified together as a lineage called the ‘Neornithes’ ( = “New Birds”), which also contains their last common ancestor and all of its other descendants. It is not yet [and might never be] clear to us whether certain fossils from the later Mesozoic and the earliest parts of the following Cenozoic Era (the “Age of Mammals”) were members of surviving Neornithean lineages, ‘basal’ Neornithes descended from the same shared ancestor but in separate branches that died out relatively early, or even “pre-Neornithes” whose lineages branched off from the Avian family tree after the Hesperonithiformes (or possibly after the Ichthyornithes, with the Hesperornithiformes having arisen before rather than after those…) but before that Neornithean common ancestor.

It seems to be the case that the Enantiornithes and any last surviving lines of the ‘basal’ types died out at the ‘K-Pg Event’, the “Doom of the Dinosaurs”, and that so too did all Euornithean lineages which had branched off from the Avian family tree before the Hesperornithiformes… On RL Earth, the Hesperonithiformes also died out at that point, but in the IDU’s reality at least one species survived it and this lineage continued (with some returned diversity, for a while) until late in the Miocene epoch.


The most basal division within the surviving Neornithes is between the ‘Palaeognathae;’ who retain certain “primitive” features of the jaw & palate even as adults, and the far more numerous ‘Neognathae’ in which those traits do not persist past the embryonic stage or — at most — are lost during the birds’ growth from chicks into adults. It is not clear which of these patterns existed in the last common ancestor of the two groups, because it is possible that the “Neognath”-type jaw & palate did not evolve until after the lineages had already diverged genetically anyway but it is also possible that the “modern” structures had evolved earlier so that the presence of the older system in the surviving Palaeognathes is just an example of ‘neoteny’ (an evolved persistence of formerly-“childhood” features into adulthood) instead. They have only short tails, or even none at all, but — unlike the situation in all other surviving Avian taxa — their caudal vertebrae are not fused to form “true” pygostyles.
The most basal division within the surviving Neognathae, confirmed on the basis of molecular& genetic studies from the 1990s onwards, is between the ‘Galloanserae’ (containing the Order ‘Galliformes’, which is the Chickens & their close relatives; the order ‘Anseriformes’, which is the Geese & their close relatives; and some less well-known groups, now extinct in RL although one of them survives in the IDU’s reality, that were more closely related to these than to any other surviving Orders…) and the far more numerous ‘Neoaves’ ( = “New Birds”… again; containing all of the other surviving lineages).

Several rival patterns of evolution-based classification have been proposed for the Neoaves, and it has not yet been possible to determine for certain which [if any] of these is correct: Even genetic studies cannot yet give us a definitive answer, due to the length of time through which the various branches have been diverging and the amount of random variation that has therefore been possible during that process. We can be reasonably sure that most of the Orders are divided between seven ‘Super-Orders’, but the precise relationships between these larger groups remain unclear and three Orders that exist in RL (at least two of which also exist in the IDU’s reality) — plus at least two Orders that are endemic to the IDU’s reality — currently have to be left as singletons instead.

Super-Orders
Columbimorphae = Pigeons & relatives.
Mirnadornithes = Flamingos, Grebes, & [extinct] relatives.
Cuculimorphae = Cuckoos & relatives.
Strisores = Swifts, Hummingbirds, & relatives; Nightjars & relatives.
Phaetonimorphae = Tropic Birds & [extinct] relatives; Kagu & Sun-Bittern & [extinct] relatives.
Aequiornithes = ‘Higher Water Birds’ (although the latter term is sometimes extended to include the Eurypterygimorpha as well…).
Telluraves = ‘Higher Land Birds’, divided into ‘Afroaves’ (earliest evolution apparently in Africa) & ‘Australaves’ (earliest evolution apparently in South America, Australia, and presumably pre-glaciated Antarctica while that still formed a habitable connection between those other two continents…). Among the Australaves is the Order ‘Passeriformes’ ( = “Sparrow-like Birds”, commonly called the “Perching Birds”, with most of its members in the Sub-Order ‘Oscines’ which is the “Songbirds”), which alone contains over half of the “modern” Bird ‘Species’ and approximately half of the surviving Bird ‘Families.

Separate Orders
Charadriiformes = ‘Shorebirds’ or ‘Waders’ (including, despite that common name, both some purely land-based groups and the more maritime Gulls and Auks…).
Gruiformes = Cranes, Rails, & relatives.
Opisthocomiformes = Hoatzin & [extinct] relatives.
Ibidorostriformes = Ibis-beaks & close relatives ( endemic to the IDU; apparently not closely linked to the RL ‘Ibis-bill’, which is in the Order Charadriiformes instead).
Terpsichoraviformes = ‘White Dancers’ & close relatives (endemic to IDU).

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Early Lineages

Post by Bears Armed » Fri Feb 21, 2020 7:44 pm

† Hesperornithiformes: Hesperornithidae

[Order undefined]: Sequiavidae *

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Palaeognathae

Post by Bears Armed » Fri Feb 21, 2020 7:44 pm

Lithornithiformes: Lithornithidae
Struthioniformes: Struthionithidae
Rheiformes: Rheidae
† Aepornithiformes: Aepornithidae
Casuariformes: Casuaridae
Casuarifomes: Dromaeidae
Tinamiformes: Tinamithidae
Apterygiformes: Apterygidae
† Dinornithiformes: Dinornithidae

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Neognathae: Galloanserae

Post by Bears Armed » Fri Feb 21, 2020 7:45 pm

(Pangallifromes)

[Order undefined]: Sylviornithidae

† Galliformes: Quercymegapodidae
Galliformes: Megapodidae
Galliformes: Cracidae
Galliformes: Odontophoridae
Galliformes: Phasianidae (inc. Meleagridae, Tetraonidae; probably inc. Numididiae)
Galliformes: Neoperdicidae *
Galliformes: *
Galliformes: *

Palaeogallfiromes *: † Palaeoperdicidae *
Palaeogallfiromes *: †
Palaeogallfiromes *: †
Palaeogallfiromes *: †
Palaeogallfiromes *: †
Palaeogallfiromes *: †
Palaeogallfiromes *: Geoaquilidae *

† Gastornithiformes: Gastornithidae

Anseriformes: † Presbyornithidae
Anseriformes: † Bathyornithidae
Anseriformes: † D ornithidae
Anseriformes: Anhimidae
Anseriformes: Anseranatidae
Anseriformes: Anatidae

(†) Odontopterygiformes: † Pelagornithidae
(†) Odontopterygiformes: † ornithidae *
(†) Odontopterygiformes: Neopelagornithidae *

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Neognathae: Neoaves: Columbimorpha and Miranandornithes

Post by Bears Armed » Fri Feb 21, 2020 7:45 pm

TBA

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Neognathae: Neoaves: Cuculimorpha and Strisores and Opisthocomiformes

Post by Bears Armed » Fri Feb 21, 2020 7:46 pm

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Neognathae: Neoaves: Charadriiformes and Gruiformes

Post by Bears Armed » Fri Feb 21, 2020 7:46 pm

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Neognathae: Neoaves: ‘’Higher Water Birds’

Post by Bears Armed » Fri Feb 21, 2020 7:46 pm

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Neognathae: Neoaves: Telluraves: Afroaves

Post by Bears Armed » Fri Feb 21, 2020 7:47 pm

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Neognathae: Neoaves: Telluraves: Australvaes (I)

Post by Bears Armed » Fri Feb 21, 2020 7:47 pm

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Neognathae: Neoaves: Telluraves: Australvaes (II)

Post by Bears Armed » Fri Feb 21, 2020 7:47 pm

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Neognathae: Neoaves: Telluraves: Australvaes (III)

Post by Bears Armed » Fri Feb 21, 2020 7:48 pm

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