The Great Avian Dinosaur Bird Mystery
or
Searching for the Avian Dinosaurs
or
Did the Avian Dinosaurs really survive the K-Pg Extinction Event?
or
Should we really call current day birds feathered theropod dinosaurs?
or...
Honestly I could keep going. This one really peeves me. Sort of. Maybe just a little. So there I was, it was a pretty good day...
Sunday 11 April 2021
pretty much started like most days. Except I had found some of my page references were displaying Greek words whereas before I thought this would not be the case and deleted a lot of these from some wikipedia references I had used, like
The Plesiosauria (/ˌpliːsiəˈsɔːriə, -zi-/; Greek: πλησίος, plesios, meaning "near to" and sauros, meaning "lizard")
https://en.wikipedia.org/wiki/Plesiosauria
So I decided to go back and check all my references and put any deleted Greek words back in. This was a long list and took a bit of time. Lot of animals, lot of dinosaurs. The day was slowly coming to an end and I eventually got to the very last dinosaur. The Velociraptor. It had to be the Velociraptor.
The references I had cobbled together were interesting. It was a mixture of wikipedia and google and listed a speed of 64 km/hr. The speed had been obtained from a google search but I noticed that google was now giving 40 km/hr. So I did a bit of searching to find out where the original google search speed of 64 km/hr might have come from and I found it:
Velociraptor
The Velociraptor weighed up to 15 kilograms (kg). It had a length of 2 meters (m) and a height of 2 meters (m). This dinosaur could run up to 64 kilometers per hour (km/h) and lived during the Cretaceous Period
http://www.asfg.mx/es/kids/special_pages/dino_museum/files/dino_measurement_book.pdf
But the dimensions weren't right. The actual Velociraptor height is a little more than half a meter, and length a little less than 2 meters with half of that tail. About the size of a turkey. They had a diagram of the dinosaur with scale to a human. And taller. There was a link at the bottom of the pic which I followed*. Also zooming on the pic revealed the same info: Jurassic Park. I had pulled the info from the wrong dinosaur using the search info from google. Which has obviously been updated to give a more reasonable value.
* http://images.wikia.com/jurassicpark/images/8/8e/Velociraptor_macho.jpg
Velociraptor (commonly referred to as "raptor") is one of the dinosaur genera most familiar to the general public due to its prominent role in the Jurassic Park films. In real life, however, Velociraptor was roughly the size of a turkey, considerably smaller than the approximately 2 m (6.6 ft) tall and 90 kg (200 lb) reptiles seen in the novels and films (which were based on members of the related genus Deinonychus).
http://web.archive.org/web/20230408054625/https://en.wikipedia.org/wiki/Velociraptor
Now things were about to get a bit worse, though resolved by the time I went to sleep. Deciding to check further to see if I missed anything else I noticed that the timeline fell far short of 66 Ma:
Velociraptor
Temporal range: Late Cretaceous, ~75–71 Ma
Velociraptor (/vəˌlɒsɪˈræptər, vəˈlɒsɪræptər/; lit. 'swift thief') is a genus of small dromaeosaurid dinosaur that lived in Asia during the Late Cretaceous epoch, about 75 million to 71 million years ago.
http://web.archive.org/web/20230408054625/https://en.wikipedia.org/wiki/Velociraptor
The presentation I was working on was mainly in two parts, the first part not really dependent on the K-Pg extinction point so this did not really matter that much though it did throw me at first [1]. I thought I had to get a few more dinosaurs to replace the smaller ones I had used: Velociraptor, Bagaceratops, Mononykus, and a couple of others. So I started to look for some small dinosaurs. I found a very interesting page at
Dinosaurs in the late Cretaceous
(101 to 66 million years ago)
139 dinosaurs from the Late Cretaceous
The Natural History Museum, London
https://www.nhm.ac.uk/discover/dino-directory/timeline/late-cretaceous/gallery.html
I just needed a few small dinosaurs up to 66 Ma. Surely I would find a few. The page looked very interesting so I decided to start at the bottom. That's where the Velociraptor was. Just a few quickly, choosing the smaller looking ones...
Zalmoxes: Late Cretaceous, 69 million years
Velociraptor: Late Cretaceous, 74-70 million
Urbacodon: Length: 1.0m, Late Cretaceous, 95 million years. [Definitely looks like a small bird]
Jumping from here. They had a link to small dinosaurs and this opened up:
Small Theropods
Small carnivores, herbivores and omnivores that walked on two legs and often had feathers. Birds are part of this group.
The Natural History Museum, London
https://www.nhm.ac.uk/discover/dino-directory/body-shape/small-theropod/gallery.html
I may have just hit paydirt. If this pans out OK then this page will slowly come to an end and I will probably leave it here just for historical interest, even if I was completely wrong. Actually what happened earlier is that I stayed on the first page looking for some small dinosaurs going to 66 Ma. I wasn't finding any and thought to myself, this is crazy? What am I doing? There should be some small dinosaurs to 66 Ma. What about the birds? The Avian Dinosaurs? Was I seeing any of those? And wouldn't they go to 66 Ma and beyond? We are told that:
Of the many great dinosaurian lineages, only the birds made it through the mass extinction at the end of the Cretaceous - but nobody is quite sure why.
p.162.
Flying Dinosaurs: How fearsome reptiles became birds, John Pickrell, 2014.
Early members of the palaeognath lineage survived (the group that includes ostriches and emus), as did members of the wildfowl and gamebird lineage, as
did members of the lineage that led to seabirds, hawks, perching birds, and so on.
Why these bird groups survived when other dinosaur groups didn't is a good question, and one that hasn't been answered satisfactorily. p.208.
Dinosaurs: How they lived and evolved. Darren Naish & Paul M. Barrett, CSIRO Publishing, 2018.
Birds are feathered theropod dinosaurs and constitute the only known living dinosaurs. ... According to DNA evidence, modern birds (Neornithes) evolved in the Early to Late Cretaceous, and diversified dramatically around the time of the Cretaceous–Paleogene extinction event 66 mya, which killed off the pterosaurs and all non-avian dinosaurs.
http://web.archive.org/web/20230413140702/https://en.wikipedia.org/wiki/Bird
According to this, the birds were there as avian dinosaurs and survived the K-Pg extinction event while the non-avian dinosaurs did not. So we should be able to find a heap of avian dinosaurs at the 66 Ma point and into the Paleocene [66 - 56 Ma].
Anyway with this new page this looked promising. Archaeopteryx was there along with a lot of other small bird-like dinosaurs down to Urbacodon with the Velociraptor listed last. Looking at the small bird-like ones I began to construct a list...
Unenlagia. Length: 2.4m, Late Cretaceous, 94-86 million
Sinovenator. Length: 1.0m, Early Cretaceous, 127-121 million
Sinornithosaurus. Length: 2.0m, Early Cretaceous, 122-120 million
Sinocalliopteryx. Length: 2.37m, Early Cretaceous, 125 million years
Shuvuuia. Length: 0.6m, Late Cretaceous, 75-81 million
Shanag. Length: 0.45m, Early Cretaceous, 126-142 million
Rinchenia. Length: 2.5m, Late Cretaceous, 72-68 million
Protarchaeopteryx. Length: 2.0m, Early Cretaceous, 122-120 million
from:
The Natural History Museum, London
https://www.nhm.ac.uk/discover/dino-directory/body-shape/small-theropod/gallery.html
OK break here. The last one struck me as curious. Listed as 'before Archaeopteryx' I thought maybe this should have been a bit smaller? So I checked wikipedia:
Protarchaeopteryx had long legs, and could have been a quick runner. It had well-developed, vaned feathers extended from a relatively short tail; the hands were long and slender, and had three fingers with sharp, curved claws. Its bones were hollow and bird-like, and it possessed a wishbone. At around 1 metre (3.3 ft) in length, it would have been larger than Archaeopteryx. ... Protarchaeopteryx also had symmetrical feathers on its tail. Since modern birds that have symmetrical feathers are flightless, and the skeletal structure of Protarchaeopteryx would not support flapping flight, it is assumed that it was flightless as well.
http://web.archive.org/web/20230326043218/https://en.wikipedia.org/wiki/Protarchaeopteryx
Some very interesting information there. Now back to the list:
Nomingia. Length: 1.6m, Late Cretaceous, 72-68 million
Mononykus. Length: 1.0m, Late Cretaceous, 81-68 million
Microraptor. Length: 0.8m, Early Cretaceous, 125-122 million
Khaan. Length: 1.8m, Late Cretaceous, 81-75 million
Heyuannia. Length: 2.0m, Late Cretaceous, 72-68 million
Hagryphus. Length: 3.0m. No period given.
from:
The Natural History Museum, London
https://www.nhm.ac.uk/discover/dino-directory/body-shape/small-theropod/gallery.html
OK going elsewhere for some info on this one:
Hagryphus
Temporal range: Late Cretaceous, 75.95 Ma
Hagryphus (meaning "Ha's griffin") is a monospecific genus of caenagnathid dinosaur from southern Utah that lived during the Late Cretaceous (upper Campanian stage, 75.95 Ma)
Radiometric dating of rocks from slightly below the rock bed where the fossil was found indicates that the specimen died 75.95 million years ago.
In 2003 Zanno & Sampson reported the new find as a member of the Caenagnathidae. However, in 2005 they limited the precision of the determination to a more general Oviraptorosauria.
Oviraptorosaurs ... Evidence suggests that they were feathered and some paleontologists consider them to be true birds
http://web.archive.org/web/20230326043250/https://en.wikipedia.org/wiki/Hagryphus
And that is interesting. Back to the list...
Confuciusornis, 'Confucius bird'. Length: 0.25m, Early Cretaceous, 127-121 million
Conchoraptor. Length: 1.5m, Late Cretaceous, 81-76 million
Citipati. Length: 2.1m, Late Cretaceous, 81-75 million
Chirostenotes. Length: 1.7m, Late Jurassic,* 79-67 million years
Caudipteryx 'tail feather'. Length: 1.0m, Weight: 2kg, Early Cretaceous, 125-122 million
Buitreraptor. Length: 1.3m, Late Cretaceous, 99-90 million
Beipiaosaurus. Length: 2.0m, Early Cretaceous, 127-121 million
Bambiraptor. Length: 1.0m, Late Cretaceous, 84-71 million
Avimimus 'bird mimic'. Length: 1.5m, Late Cretaceous, 80-75 million
Archaeornithomimus. Length: 3.5m, Late Cretaceous, 95-70 million
and last but not least:
Archaeopteryx 'ancient wing'. Length: 0.5m, Late Jurassic, 147 million years ago
from:
The Natural History Museum, London
https://www.nhm.ac.uk/discover/dino-directory/body-shape/small-theropod/gallery.html
* this can't be right. It's probably a typo and should be Late Cretaceous.
It is unlikely this list is exhaustive. Also I may have missed a few and possibly got a few non-avian dinosaurs in my selection. I did try to choose the ones that looked like birds but that's just from what they were displaying. I noticed that other sites may give a more bird-like pic for a dinosaur so this sort of selection process may not be that simple without doing a full background check on each one.
And it appears that a small dinosaur may look like a bird but not be fully acceptable, for example, Alvarezsaurus:
Alvarezsaurus
Temporal range: Late Cretaceous, 86–83 Ma
Alvarezsaurus (/ˌælvərɛzˈsɔːrəs/; "Alvarez's lizard") is a genus of alvarezsaurid dinosaur from the Late Cretaceous, living in Argentina approximately 86 - 83 million years ago. It was a small dinosaur, measuring 1–1.4 m (3.3–4.6 ft) long and weighing approximately 3 kg (6.6 lb).
Alvarezsaurus is considered basal to better-known members of its family, such as Mononykus and Shuvuuia. It has been alternately classified with both non-avian theropod dinosaurs and early birds, but a move of the alvarezsaurids to be recognized as more closely related to neornithine birds proved controversial despite being supported by earlier studies.
http://web.archive.org/web/20230326043028/https://en.wikipedia.org/wiki/Alvarezsaurus
It looks like a bird. So yes, this selection process is far from simple. I simply chose those that looked like birds. And if my selection is still a reasonable sample of avian dinosaurs [allowing for a few non-avian dark horses] then there are some very interesting conclusions to draw.
Update on this. Found a better list. An A to Z list of something like 43 feathered dinosaurs from John Pickrell's book "Flying Dinosaurs: How fearsome reptiles became birds." This gives an interesting list from Anchiornis huxleyi [161-156 Ma] to Yutyrannus huali [125-122 Ma] with the most recent at 66 Ma [Anzu wyliei and Ornithomimus edmontonicus and Rahonavis ostromi].
I was aware of the Anzu dinosaur before. It is not on the nhm site but I had previously run across it. Though looking like a bird, at up to 300kg I thought this a bit heavy. Our heaviest flying bird in the world is the Andean Condor at up to 15kg. Still, an interesting one and could go on my list.
http://flyingdinosaurs.net/a-z-of-feathered-dinosaurs/
https://en.wikipedia.org/wiki/Condor
Ornithomimus edmontonicus is interesting because its period is given as 80-65 Ma but listed as Cretaceous so this is possibly meant to be to 66 Ma as given on wikipedia.
Similarly Rahonavis ostromi has period 71-65 Ma for the Late Cretaceous, so again possibly meant to be 71-66 Ma but wikipedia only gives 70 Ma.
https://en.wikipedia.org/wiki/Ornithomimus
https://en.wikipedia.org/wiki/Rahonavis
Avian Dinosaurs Did Not survive the K-Pg Extinction Event
None of the dinosaurs of the ones I selected from the museum site went to the K-Pg Extinction Event at 66 Ma. But a small number from Pickrell's list did:
Rahonavis ostromi
Ornithomimus edmontonicus
Anzu wyliei
with a questionmark on Rahonavis.
And something interesting... Apparently there are some Cretaceous birds which appear to be catalogued differently to avian dinosaurs [go figure]. So we can add to the general list. Some sections gave a choice on Late Cretaceous which I obviously chose to simplify this search:
Vegavis: Temporal range: Maastrichtian ~68–66 Ma
Polarornis: Temporal range: Maastrichtian ~66 Ma
Brodavis: Temporal range: Late Cretaceous, 80.5–66 Ma
Cimolopteryx: Temporal range: Late Cretaceous, 68-66 Ma
Gurilynia: Temporal range: Late Cretaceous, 70–66 Ma
Avisaurus: Temporal range: Late Cretaceous: 70.6-66 Ma
Ceramornis: Temporal range: Late Cretaceous, 66 Ma. Depends how you interpret "shortly before"
Graculavus velox: 70.6 to 66.043 Ma
Laornis: 70.6 to 66.043 Ma
Palintropus: Temporal range: Late Cretaceous, 76.5–66 Ma
Potamornis: Temporal range: Late Cretaceous, 67-66 Ma
Torotix: Temporal range: Late Cretaceous, 66.9-66 Ma
Tytthostonyx: Temporal range: Late Cretaceous, 66 Ma
But that appears to be as far as they got.
If overall we have a reasonable sampling of the avian dinosaurs and Cretaceous birds then I would have to conclude that they DID NOT survive the K-Pg Extinction Event! And this does make the previous quotes very interesting:
"Of the many great dinosaurian lineages, only the birds made it through the mass extinction at the end of the Cretaceous"
If the sampling here is a reasonable representation, then NONE of the avian dinosaurs went "through the mass extinction at the end of the Cretaceous"!
"Why these bird groups survived when other dinosaur groups didn't is a good question"
If the sampling here is a reasonable representation, then they didn't survive at all. A small number made it up to the K-Pg Extinction Event and that's as far as they got!
"modern birds (Neornithes) evolved in the Middle to Late Cretaceous, and diversified dramatically around the time of the Cretaceous–Paleogene extinction event 66 mya, which killed off the pterosaurs and all non-avian dinosaurs."
If the sampling here is a reasonable representation, then the avian dinosaurs were killed off along with the non-avian dinosaurs at the K-Pg Extinction Event. So perhaps the quote should be amended to read "which killed off the pterosaurs and all dinosaurs."
It is possible I may have missed some, but with Pickrell's list added, this is how it looks.
Current Day Birds Avian Dinosaurs?
Which brings us to the question as to why are we now calling our current day birds avian dinosaurs?
Birds
Temporal range: Late Cretaceous – present, 72–0 Ma
Birds are feathered theropod dinosaurs and constitute the only known living dinosaurs.
Based on fossil and biological evidence, most scientists accept that birds are a specialised subgroup of theropod dinosaurs and, more specifically, members of Maniraptora, a group of theropods which includes dromaeosaurids and oviraptorosaurs, among others.
Most studies agree on a Cretaceous age for the most recent common ancestor of modern birds but estimates range from the Early Cretaceous to the latest Late Cretaceous. Similarly, there is no agreement on whether most of the early diversification of modern birds occurred before or after the Cretaceous–Palaeogene extinction event.
https://web.archive.org/web/20230103025702/https://en.wikipedia.org/wiki/Bird
Seems straightforward while still being a bit of a muddle.
As for labelling, if it looks like a duck and walks like a duck and quacks like a duck it could be a duck. So sure, we could call them avian dinosaurs. But this does not mean the birds are really dinosaurs just that they may look like them. Remember that some of the dinosaur names have "mimic" built into them:
Archaeornithomimus 'ancient bird mimic'
Avimimus 'bird mimic'
Harpymimus 'harpy mimic'
Pelicanimimus 'pelican mimic'
There are insects that mimic others for protection such as spiders and wasps. But that doesn't make those insects spiders or wasps, just that they may look like them.
So just calling the birds avian dinosaurs does not make them actual dinosaurs any more than the name Pelicanimimus makes that dinosaur a pelican!
But the second part is far more controversial. If the most recent common ancestor of modern birds is back to the Cretaceous that suggests there is no clear fossil record going back to there. In other words we have dinosaur birds in the Cretaceous and we have modern birds. With no fossil evidence supporting the avian dinosaurs going through the K-Pg Extinction Event this makes a complete mess of everything. We can't really say the birds survived the Extinction Event if the avian dinosaurs did not.
And if the birds can't really be tracked back to the dinosaurs, the big question then is, just where did they come from?
As a Christian I have no problem with that question. None whatsoever.
And a very interesting quote:
Birds are feathered theropod dinosaurs and constitute the only known living dinosaurs.
https://web.archive.org/web/20230103025702/https://en.wikipedia.org/wiki/Bird
Now this may sound like a backflip, but I am quite comfortable with this quote from wikipedia. Considering that the non-avian dinosaurs never existed as living breathing creatures at any time in the past then we could label the birds as the only living dinosaurs that have ever existed and the only real dinosaurs. In this respect I have no problem with this labelling.
And if anyone doesn't like these conclusions that I have drawn here I suppose they could blame it all on the Velociraptor!
REFERENCES
1. By the time I got to bed I realized, of course, the first part of my presentation was not dependent on the 66 Ma point so the small dinosaurs I had chosen were still OK to use. But by this time I had hit the curious problem of the avian dinosaurs and had decided to have a good look for them. The search continued in earnest the next day.
Update on this. I finally decided anyway to replace the dinos as I felt this would strengthen the argument of my presentation. That said, sadly the Velociraptor was one of the dinosaurs that was dropped.
Note: when I mention that the K-Pg Extinction Event killed off all the non-avian dinosaurs this does not necessarily mean that I believe this or that I believe any of these dinosaurs ever existed as living breathing animals at any time in the past.
Dinosaurs in the late Cretaceous
and
Small Theropods
The Natural History Museum, London
https://www.nhm.ac.uk/discover/dino-directory/timeline/late-cretaceous/gallery.html
https://www.nhm.ac.uk/discover/dino-directory/body-shape/small-theropod/gallery.html
A-Z of feathered dinosaurs
http://flyingdinosaurs.net/a-z-of-feathered-dinosaurs/
states 'This is an extract from':
John Pickrell, 2014, Flying Dinosaurs: How fearsome reptiles became birds, NewSouth Publishing.
Ma - million years ago.
Ba - billion years ago.
K-T, K-Pg boundary, extinction event
Cretaceous–Paleogene extinction event
The Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary (K–T) extinction) was a sudden mass extinction of three-quarters
of the plant and animal species on Earth, approximately 66 million years ago.
https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event
Velociraptor are well known for their role as vicious and cunning killers thanks to their portrayal in the 1990 novel Jurassic Park by Michael Crichton and its 1993 film adaptation, directed by Steven Spielberg. The "raptors" portrayed in Jurassic Park were actually modeled after the closely related dromaeosaurid Deinonychus. ... Crichton met with the discoverer of Deinonychus, John Ostrom, several times at Yale University to discuss details of the animal's possible range of behaviors and appearance. Crichton at one point apologetically told Ostrom that he had decided to use the name Velociraptor in place of Deinonychus because the former name was "more dramatic". According to Ostrom, Crichton stated that the Velociraptor of the novel was based on Deinonychus in almost every detail, and that only the name had been changed.
https://en.wikipedia.org/wiki/Velociraptor
A real big headache
Since the 1990s some dinosaur fossils with feathers started turning up. It is now accepted by evolutionists that many, but not all groups, of dinosaurs had some feathers. And this will be a real pain for those involved in making movies with any dinosaurs that have shown some feathers in their fossils. Unfortunately for the Jurassic Park/World bunch, Deinonychus is one of them. For those watching the movies, that's the Jurassic Park Velociraptor. They may possibly try to make some adjustment. The next few movies should be very interesting!
https://en.wikipedia.org/wiki/File:Deinonychus_ewilloughby.png
Reconstruction of dromaeosaur dinosaur Deinonychus antirrhopus; proportions based on Scott Hartman's skeletal diagram.
Attribution: Emily Willoughby
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
Deinonychus: the Jurassic Park "Velociraptor"
Deinonychus: the Jurassic Park "Velociraptor"
Deinonychus: the Jurassic Park "Velociraptor"
Just doesn't look the same, does it?
Cute? Don't let it fool you. Skeletally, this is the same as the "Velociraptor" in the movies, with teeth and claws etc. If it had actually lived, this dinosaur may have been as deadly as depicted in the movies!
https://commons.wikimedia.org/wiki/File:Deinonychus_model_Baltow.jpg
Deinonychus antirrhopus model in Baltów (Poland).
Attribution: Meridas (Vladimír Socha)
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
Remix: cropped with text added. Image remix under same license.
https://commons.wikimedia.org/wiki/File:Velociraptor_Restoration.png
Artistic restoration of Velociraptor mongoliensis
Attribution: Fred Wierum
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
Remix: cropped with text added. Image remix under same license.
https://en.wikipedia.org/wiki/File:Velociraptor_mongoliensis.jpg
Attribution: Nobu Tamura (http://spinops.blogspot.com)
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license.
https://commons.wikimedia.org/wiki/File:Pelecanimimus_(update).png
Attribution: Conty
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
Remix: removed extra skull and added text.
Pelican
https://www.publicdomainpictures.net/en/view-image.php?image=89184&picture=pelican-resting-on-piling
License: CC0 Public Domain
Cropped and added text.
Stephen Buckley
E-mail: greatesthoax [at] duck.com
Last revised: 22 Apr 2023.
Construction started 12 Apr 2021.
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Page design/construction Stephen Buckley 2021.