• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
Where premium quality meets exceptional value. ZEISS Conquest HDX.

Time calibration and Linnean ranks in birds (1 Viewer)

Tell us more
OK so the core Tyrannidae is intact with all represented clades less than 15 my old. Perhaps I should have written Tyrannides.
Anyway Pipromorphidae and Tachurisidae separate - no surprises!
Platyrinchidae has a split around 18mya between Platyrinchus and Neopipo
Tityridae has a similar but slightly older split between Pachyramphus and Schiffornis
Both interesting!

Cotingidae is represented by Snowornis, Pyroderus, Phytotoma, & Ampelioides. Each branch is older than 15 myo.
There are other interesting suboscine split ages but I'm not typing all that out!😄

On to the Turdidae
The oldest branch is around 20 myo - Sialia + Grandala
Next is at 19 mya between (Myadestes + Neocossyphus) and the rest of Turdidae
Then between Sialia & Grandala at around 17 mya
Neocossyphus & Myadestes split around 15 mya
Core turdids represented by Turdus, Zoothera & Catharus all separate at ages younger than 13mya

There's lots more interesting stuff but I think it would be easier to distribute photos
 
OK so the core Tyrannidae is intact with all represented clades less than 15 my old. Perhaps I should have written Tyrannides.
Anyway Pipromorphidae and Tachurisidae separate - no surprises!
Platyrinchidae has a split around 18mya between Platyrinchus and Neopipo
Tityridae has a similar but slightly older split between Pachyramphus and Schiffornis
Both interesting!

Cotingidae is represented by Snowornis, Pyroderus, Phytotoma, & Ampelioides. Each branch is older than 15 myo.
There are other interesting suboscine split ages but I'm not typing all that out!😄

On to the Turdidae
The oldest branch is around 20 myo - Sialia + Grandala
Next is at 19 mya between (Myadestes + Neocossyphus) and the rest of Turdidae
Then between Sialia & Grandala at around 17 mya
Neocossyphus & Myadestes split around 15 mya
Core turdids represented by Turdus, Zoothera & Catharus all separate at ages younger than 13mya

There's lots more interesting stuff but I think it would be easier to distribute photos
You suggested a lot of split?
 
You suggested a lot of split?
I did and on checking the book it appears that I was looking at the unconstrained tree in error earlier this morning.
The book's main results are derived from the constrained tree.
If you were to use the unconstrained ages for the core Tyrannidae there would be four clades older than 14 my which potentially could be carved off. In the constrained tree they're all younger than this age.

The other details I posted still stand.

Other families affected include Thamnophilidae, Grallariidae, Rhinocryptidae, Dendrocolaptidae, Furnariidae, Climacteridae, Maluridae, Acanthizidae, Melanocharitidae, Pachycephalidae, Cracticidae, Vireonidae, Petroicidae (4 hugely old divergences!!!), Alaudidae, Locustellidae, Pycnonotidae, Sturnidae, Muscicapidae, Nectariniidae and so on up to the 9-primes.

Timings-wise most of these fall within the range of wiggle-room that could be used to either split or combine depending on your inclination🙂
 
I did and on checking the book it appears that I was looking at the unconstrained tree in error earlier this morning.
The book's main results are derived from the constrained tree.
If you were to use the unconstrained ages for the core Tyrannidae there would be four clades older than 14 my which potentially could be carved off. In the constrained tree they're all younger than this age.

The other details I posted still stand.

Other families affected include Thamnophilidae, Grallariidae, Rhinocryptidae, Dendrocolaptidae, Furnariidae, Climacteridae, Maluridae, Acanthizidae, Melanocharitidae, Pachycephalidae, Cracticidae, Vireonidae, Petroicidae (4 hugely old divergences!!!), Alaudidae, Locustellidae, Pycnonotidae, Sturnidae, Muscicapidae, Nectariniidae and so on up to the 9-primes.

Timings-wise most of these fall within the range of wiggle-room that could be used to either split or combine depending on your inclination🙂
I would love to see your entire classification of passerines 😏
 
"Xenoperdixidae" (African Highland Partridges), Rollulidae (Asian Hill Partridges), Argusianidae (Arguses), Pavonidae (Peacocks), "Tropicoperdicidae" (Peacock-Partridges), Polyplectronidae (Peacock-Pheasants), Gallidae (Chickens), Coturnicidae (Old World Quail), Lerwidae (Snow Partridge), Ithaginidae (Blood Pheasant)
I wouldn't be so extreme, it would seem coherent to me to recognize 3 families: Rollulidae, Pavonidae and Phasianidae
 
I wouldn't be so extreme, it would seem coherent to me to recognize 3 families: Rollulidae, Pavonidae and Phasianidae
From a utility standpoint, it would make it easier to use tribes if each of these were there own separate families

Again, this is just a thought experiment and test to see how these different time periods work for calibrating rank. For Non-Passeriformes I could see using the PETM for Orders, the Eocene overall for Families, Oligocene for subfamilies, and Middle Miocene climatic optimum for tribes
 
For me it's opportunity for evolution (equal "time passed"). And then to understand which lineages evolve faster/slower and why
 
Interesting exercise! But spare a thought that times of bird diversification are extremely poorly known. They depend on theoretical models how fast DNA differences should accumulate, which cannot be assumed to transfer between lineages and times and were proven wrong in many cases. Plus dating of fossils, which are sparse and very poorly defined (think Vegavis), literally two bumps in one poorly preserved bone change the whole system.

Family divisions are extremely extreme
seems like the most "conservative" improvement over the current system.

Which shows again, that there is a consensus what groups of birds should be in the same family, but what is fluid is a method how to define such practically useful families.
I think with birds like parrots and raptors –which have a long life-span– a more conservative approach is preferable.

One problem with using generation length is that the generation time of most living birds is unknown, no matter how to magically guess it in the extinct birds...
 
I am trying to intergrate and experiment with multiple ranks to see how things look, at least for non-passeriformes.

I came out with this taxonomy for Galliformes last night, fixing Order to the approximate time of the PETM (~55 Ma), Families to before the Oligocene (>34 Ma), Subfamilies to Oligocene (~34-23 Ma), and Tribes to the Middle Miocene Climatic Optimum (~17-14 Ma)

The revised taxonomy looks like this
Megapodiiformes

Megapodiidae - Megapodes

Talegallinae - Brush Turkeys
Megapodiinae

Macrocephalonini - Maleos
Megapodiini" - Megapodes


Galliformes

Cracidae - Guans, Chachalacas, and Currasows
Numididae - Guineafowl
Ptilopachidae -Stone Partridges
Odontophoridae - New World Quail
Rollulidae - Hill Partridges

"Xenoperdixinae" - African Highland Partridges
Rollulinae - Asiatic Partridges

Rollulini - Crested Partridges and Allies
"Arborophilini" (Hill Partridges)

Phasianidae - Pheasants, Chickens, and Peafowl
Argusianinae - Arguses
Pavoninae - Peafowl
"Tropicoperdicinae" - Peacock-Partridges
Polyplectroninae - Peacock-Pheasants
Gallinae - Chickens and Francolins

Gallini - Chickens
Francolinii - Francolins

Coturnicinae - Spurfowl and Old World Quail
Tetraogallini - Snowcocks
Alectoridini - Chukars
"Pternistini" - Spurfowl
"Ammoperdicini" - Sand Partridges
Coturnicini - Old World Quail

Lerwinae - Snow Partridges
Ithagininae - Blood Pheasants
Lophophorinae - Monals and Tragopans

Lophorphorini - Monals
Tragopanini - Tragopans

Phasianinae (True Pheasants and Grouse)
Rhizotherini - Long-billed Partridges
Pucrasiini - Koklass
Meleagrini - Turkeys
Tetraonini - Grouse
Perdicini - True Partridges
Phasianini - True Pheasants
 
Honestly it seems like a reasonable arrangement, although it does mean more "low diversity" subfamilies and tribes. At least each split seems to be mostly recognizing distinct groups of birds

Probably most debatable thing is splitting off Rollulidae but keeping traditional Pavoninae and Phasianinae lumped. Recognizing three instead of two better represents the relationships (since you could better group the different subfamilies under each family), but it is a younger divergence.
 
Plus dating of fossils, which are sparse and very poorly defined (think Vegavis), literally two bumps in one poorly preserved bone change the whole system.
The age of Vegavis iaai Clarke, Tambussi, Noriega, Erickson et Ketcham, 2005 is clear: Late Cretaceous, Middle to Late Maastrihtian, 68,0-66,0 MYa.

At the moment classified as:

Parvclassis Neornithes Gadow, 1893
Cohort Neognathae Pycraft, 1900
Subcohort Galloanseres (Sibley, Ahlquist et Monroe Jr, 1988)
Superordo Anserimorphae Sibley, Ahlquist et Monroe, 1988
Ordo Vegaviiformes Worthy, Desgrange, Handley et Lee, 2017
Familia Vegaviidae

My main objection against the reasoning by Mysticete beside the arguments named by jurek (# 75) is that no fossil taxa are taken into account. There are fossil taxa, part of Neornithes older than the Eocene, you cannot simply ignore them, and he should know so as a trained paleontologist (OK, Phocidae and Cetacea) and pehaps he is, like most people, not very familiar with the fossil record of Aves.

Fred
 
Actually, I fail to see how the existence of Neornithes older than the Eocene makes any difference at all to this exercise. My calibration points are design to account for crown bird diversity. The oldest crown Neoavian is Paleocene; fossil evidence at the point seems pretty clear that the Neoavaian radiation was entirely post K-Pg. I am more then comfortable acknowledging the existence of stem Galloanseres or paleognaths in the Cretaceous; those surviving lineages would (and are) also be accorded ordinal ranks. I am only interested in making modern bird groups roughly equivalent. A PETM calibration point or a Paleocene overall calibration point produce the same result. This is simply about organizing existing diversity, which is the diversity that birders interact with and for that matter most of Ornithology.

This is also again not something to be taken seriously. This is just an exercise of a bored professor in a zoom meeting or on the couch in the evening. Feel free to ignore this thread since it seems to have nothing to do with any of your interests.

I'll worry about what to do with Argentavis and Waimanu when they invent time travel and I can go see them...
 
One point which interest me IS exactly what to do with fossil forms.

Are we looking at ranks simply as 'this split occurred at this time period of our planet's history'? Or are we thinking more 'this split is this old'?

The difference is that, if a clade diverged in the Paleocene but only survived another 10 million years, that is not the same as a clade that diverged in the Paleocene but survived to the modern era under the latter possibility. It would, of course, be entirely the same under the former.

Personally, I'm tentatively inclined to favor the latter - but freely acknowledge I lack the awareness of what sort of impact that could then have on paleontological classification. It might simply be unworkable; I would not know.
 

Users who are viewing this thread

Back
Top