Tanyrhinichthys is a basal paddlefish

Sallan et al. 2020 return again to
Tanyrhinichthys mcallisteri (Gottfried, 1987; Stack, Hodnett, Lucas and Sallan 2018; Figs. 1, 2; 15 cm length) and focus on its long rostrum, imagining a bottom-dweller, sturgeon-like lifestyle. Oddly they fail to phylogenetically connect it with extinct and extant paddlefish (Figs. 3, 4). In the large reptile tree (LRT, 1498+ taxa; subset Fig. 5) Tanyrhinichthys nests basal to paddlefish, just a few nodes away from sturgeons.

Figure 1. Tanyrhinichthys in situ and traced.

Figure 1. Tanyrhinichthys in situ and traced.

At that node
Tanyrhinichthys was a late-surviving (Carboniferous) last common ancestor of sharks + bony fish. That’s a big dealin the LRT, but it was overlooked by the authors, due to taxon exclusion and mistaking sturgeons for typical rayfin fish. Based on that phylogeny, Tanyrhinichthys had a Silurian genesis. Perhaps that is why it retained an osteostracan-like armored exoskeleton and was so difficult to nest by prior workers.

Figure 2. Skull of Tanyrhinichthys (above) with two bones relabeled. The other fish, Saurichthys, is clearly unrelated.

Figure 2. Skull of Tanyrhinichthys (above) with two bones relabeled. The premaxilla carries teeth. The nasal does not. The other fish, Saurichthys, is unrelated.

Tanyrhinichthys is an iconic transitional taxon in the LRT.
This hypothesis of interrelationships was overlooked by all prior authors due to taxon exclusion and some mislabeling of skull elements (Fig. 2), all repaired here.

Figure 2. A shark-like juvenile paddlefish (Polyodon) has teeth and lacks a paddle-snout. Compare to the adult in figure 1.

Figure 3. A shark-like juvenile paddlefish (Polyodon) has teeth and lacks a paddle-snout. Compare to the adult in figure 4.

Tanyrhinichthys had deep jaws and marginal teeth,
so it nests crownward of Chondrosteus (which had jaws, but no marginal teeth), apart from sturgeons (which lack jaws and marginal teeth). Paddlefish, like Polyodon, have teeth as juveniles (Fig. 3), but lose them as adults (Fig. 4). Both have underslung, shark-like jaws, as in Tanyrhinichthys. This taxon gives rise to sharks, ratfish, and all manner of bony fish… except sturgeons, mantas, whale sharks and kin, which are all more primitive (Fig. 5).

Figure 4. Skull of Polyodon from a diagram published in Gregory 1938, plus a dorsal view and lateral photo.

Figure 4. Skull of Polyodon from a diagram published in Gregory 1938, plus a dorsal view and lateral photo.

Stack et al. followed tradition
in assuming sturgeons are aberrant actinopterygian (ray-fin) fish. The LRT does not make assumptions, but tests all possibilities and included taxa. In the LRT (fish subset in Fig. 5) sturgeons have an extendible toothless oral cavity, the first step toward the jaws seen in Chondrosteus and all later taxa. They are not aberrant derived taxa.

Figure x. Newly revised fish subset of the LRT

Figure 5. Newly revised fish subset of the LRT

From the abstract
“The earliest ray-finned fishes (Actinopterygii) with elongate rostra are poorly known, obscuring the earliest appearances of a now widespread feature in actinopterygians.”

This may be an exaggeration. The LRT tests several long rostra taxa. Several nest close to one another. Note the authors are already assuming Tanyrhinichthys is an actinopterygian just because it has ray-fins. Only a comprehensive cladogram can determine whether or not ray fin fish are monophyletic. They are not, according to the LRT, unless sharks are included, which is not the intent of the clade name or definition.

“We redescribe Tanyrhinichthys mcallisteri, a long-rostrumed actinopterygian from the Upper Pennsylvanian (Missourian) of the Kinney Brick Quarry, New Mexico. Tanyrhinichthys has a lengthened rostrum bearing a sensory canal, ventrally inserted paired fins, posteriorly placed median fins unequal in size and shape, and a heterocercal caudal fin. Tanyrhinichthys shares these features with sturgeons, but lacks chondrostean synapomorphies, indicating convergence on a bottom-feeding lifestyle.”

Note: The authors mention sturgeons, but oddly fail to mention paddlefish, so far.

“Elongate rostra evolved independently in two lineages of bottom-dwelling, freshwater actinopterygians in the Late Pennsylvanian of Euramerica, as well as in at least one North American chondrichthyan (Bandringa rayi).”

These taxa are not ‘evolved independently.’ Actually all are related to paddlefish in the LRT. This is what tinkering does… it solves problems no one else ever thought was a problem.

“The near-simultaneous appearance of novel ecomorphologies among multiple, distantly related lineages of actinopterygians and chondrichthyans was common during the Carboniferous radiation of fishes.

This statement assumes Tanyrhinichthys is an actinopterygian. In the LRT Tanyrhinichthys precedes the shark –  bony fish split, despite having ray fins. (Don’t make the mistake of ‘Pulling a Larry Martin.’)

Quotes from ScienceDaily.com, focusing on the new paper:
“Sturgeon are considered a ‘primitive’ species, but what we’re showing is that the sturgeon lifestyle is something that’s been selected for in certain conditions and has evolved over and over again,” says Sallan, senior author on the work.

Not so, according to the LRT where sturgeons and paddlefish are related with Chondrosteus between them.

The Sallen et al. 2020 abstract,
continues to press the resemblance of Tanyrhinichys to sturgeons, while avoiding paddlefish.

“Tanyrhinichthys mcallisteri, a member of the diverse and well-preserved fish fauna within the Upper Pennsylvanian (Missourian) Atrasado Formation of the Kinney Brick Quarry (KBQ), is a small (standard length ~15 cm), elongated actinopterygian with a lengthened rostrum. New material suggests that Tanyrhinichthys was a bottom feeder morphologically similar to the modern sturgeon (Acipenser). Like sturgeon, Tanyrhinichthys had a rostrum that extended past its lower jaw and a resultant small, subterminal mouth, as well as a number of other convergent features, including a long anal fin set forward of the dorsal, large lateral line scales, and an anteriorly-deepened body with ventral insertion of the paired fins. Two other long-rostrumed actinopterygians, an unnamed taxon from Indiana and Phanerorhynchus from the U.K., are known from similarly-aged, Pennsylvanian freshwater coal deposits. Various skeletal features indicate that these long-rostrumed fishes were not closely related.

In the LRT these ‘long-rostrumed fishes’ are all related. So where are comparisons to paddlefish? They immediately follow:

“As supported by the existence of the paddlefish-like shark Bandringa in similarly aged deposits from Illinois, there was widespread convergence on a bottom-feeding freshwater morphotype amongst Pennsylvanian fishes.”

In the LRT the two Bandringa specimens do not nest with each other. One nests with paddlefish, the other not far off with Falcatus.

“Tanyrhinichthys falls into a group of fishes with short electro-sensory rostra with less skeletal support anteriorly, likely facilitating a bottom-roving feeding strategy. This group of fishes includes living taxa (sturgeon, paddlefish, and armored catfishes), along with fossil taxa such as Phanerorhynchus. Although there are some exceptions, it appears that long-rostrumed fishes are driven to evolve grossly similar structures in pursuit of distinctive life modes.”

Thus the authors make only the vaguest of connections between Tanyrhinichthys and paddlefish.

re: Gottfried 1987 (below): the clade ‘Aeduelliform’ seems to have been used only by him and him alone. A Google search revealed no other attributions or usages.


References
Gottfried MD 1987. A Pennsylvanian aeduelliform (Osteichthyes, Actinopterygii) from North America with comments on aeduelliform interrelationships.
7Paläontologische Zeitschrift 61(1):141-148.
Stack J, Hodnett JM, Lucas S and Sallan L 2018. Tanyrhinichthys, a long-rostrumed Carboniferous ray-finned fish (Actinopterygii), and the evolution of elogate snouts in fishes. Journal of Vertebrate Paleontology abstracts 2018.
Sallan L, Lucas SG, Hodnett J-P and Stack J 2020. Tanyrhinichthys mcallisteri, a long-rostrumed Pennsylvanian ray-finned fish (Actinopterygii) and the simultaneous appearance of novel ecomorphologies in Late Palaeozoic fishes. Zoological Journal of the Linnean Society, 2020; DOI: 10.1093/zoolinnean/zlaa044

Ancient “sturgeon” was not a sturgeon

https://www.sciencedaily.com/releases/2020/06/200622133022.htm

http://reptileevolution.com/polyodon.htm

Flatheaded Triassic Annaichthys enters the LRT

Earlier we looked at the holotype of Pholidophorus.

Figure 1. Annaichthys holotype in situ.

Figure 1. Annaichthys holotype in situ.

Almost finless Annaichthys is definitely a pholidophorid,
but it also nests with eel-like Tarrassius at the base of the Lepisosteus (the extant long nose gar) clade. Several transitional taxa separate these two distinct taxa.

Figure 2. Annaichthys skull in situ and reconstructed.

Figure 2. Annaichthys skull in situ and reconstructed.

Annaichthys pontegiurinensis (Arratia 2013; MCSNB 11282a,b,c; Triassic) is known from one fossil in part and two counterparts. This taxon nests with Tarrasius. Small fins are visible on the fossil with ventral and lateral surfaces exposed. Pholidophorids are traditionally considered actinopterygii, but in the large reptile tree (LRT, 1675+ taxa) they nest near the base of a large clade of stem lobefins. That means, over deep time, tetrapods are also pholidophorids.

Figure x. Updated subset of the LRT, focusing on basal vertebrates = fish.

Figure x. Updated subset of the LRT, focusing on basal vertebrates = fish.

Previously Tarrasius entered the LRT
despite a distinctive tadpole-like morphology (straight tail and lacking pelvic fins).

Pholidophorids are traditionally considered extinct,
but in the LRT the arowana, Osteoglossum, is an extant pholidophorid. So are tetrapods.

According to Arratia 2020,
“Pholidophoriformes Berg (1937) is a poorly known assemblage of Mesozoic actinopterygian fishes whose close association with teleosts and their closest relatives makes them an important group for the understanding of the modern radiation of fishes.”

“More recently, however, the monophyly of †Pholidophoriformes and the relationships of its constituent families have been cast into doubt. The rhombic ganoid scales with peg-and-socket articulation and the elongate or fusiform body shape shared by †pholidophoriforms are now recognized to have a broad distribution within primitive actinopterygians. As a result, the nature and phylogenetic affinities of the various taxa constituting †Pholidophoriformes (collectively referred to here as ‘pholidophoriforms’) are uncertain.”

In Arratia’s 2020 memoir,
Annaichthys was considered, but Tarrasius was not. “Pholidophorus and its somewhat vague original definition (Agassiz, 1832), which has led to it becoming a taxonomic wastebasket for fish possessing rhombic ganoid scales.”

Arratia disputed Berg 1937 when reporting,
“Feature 1, scales and bones built as in Lepidosteus (= Lepisosteus), is difficult to evaluate because it could refer to many different aspects of the scale (e.g., thickness, rnamentation).Even so, there are major differences in the scales and bones of taxa identified as pholidophoriforms by Berg (1937), so it is not clear how this feature unites the group.”

Berg listed 12 traits he thought were shared by Pholidophormes.
In doing so Berg ‘pulled a Larry Martin‘. There is only one way to define any clade and that is by phylogenetic analysis as it determines a last common ancestor. Of course, this may change as taxa are added, so start with a wide gamut analysis like the LRT.

Arratia’s 2020 figure 95 cladogram
nested two dissimilar taxa, Amia (the bowfin) and Lepisosteus (the long nose gar) as outgroup taxa to a clade Teleosteomorpha, which included Pachycormus in a basal clade. The LRT includes more outgroup taxa and does not support this topology.


References
Arratia G 2020. Morphology, taxonomy, and phylogeny of Triassic pholidophorid fishes (Acinopterygii, Teleostei). Memoir Journal of Vertebrate Paleontology 33:sup1:1–138.

Pholidophoridae Woodward 1890

 

 

Labidolemur enters the LRT as a ‘freakish dead-end’ taxon

Labidolemur kayi
(Matthew and Granger 1921; Eocene, 55mya; Fig. 1) was re-described by Silcox et al. 2010 with µCT scans that provided cranial cavity and other never-before-seen details. The several skeletons analyzed in the publication were recovered from freshwater limestone in the Bighorn Basin by co-author Peter Houde of New Mexico State University.

Figure 1. Co-author Jonathan Block holding up the rather complete and articulated skeleton of Labidolemur still encased in a bit of reddish matrix.

Figure 1. Co-author Jonathan Block holding up the rather complete and articulated skeleton of Labidolemur still encased in a bit of reddish matrix.

According to a publicity release
(link below) “Researchers said the new information will aide future studies to better understand the origin of primates. Scientists have disputed the relationships of Apatemyidae, the family that includes L. kayi, for more than a century because of their unusual physical characteristics. With can opener-shaped upper front teeth and two unusually long fingers, apatemyids have been compared to a variety of animals, from opossums to woodpeckers.”

When added to
the large reptile tree (LRT, 1698+ taxa) Labidolemur unsurprisingly nests with Apatemys, within Glires (gnawing placentals). Labidolemur and Apatemys are virtually identical according to the LRT scores, but proportional differences can still be discerned when the two skulls are side-by-side.

So Labidolemur will not help us,
“better understand the origin of primates.”

Silcox et al. 2010 wrote:
“To test all of the hypotheses that have been suggested, it is necessary to include a very broad range of eutherians, including other apatemyids, eulipotyphlans, ‘proteutherians’ (leptictids and palaeoryctids), primates and other euarchontans, and any other groups that might be relevant for accurately reconstructing basal states for larger clades that include those taxa (e.g. carnivorans and gliroids). To this end we have assembled a matrix of 33 in-group taxa and one out-group (Ukhaatherium nessovi) that were assessed for 240 morphological characters (68 postcranial, 45 cranial, and 127 dental.”

Figure 2. Cladoram from and Bloch 2020 lacking many pertinent taxa.

Figure 2. Cladoram from Silcox et sl. 2020 lacking many pertinent taxa. See text for list.

A broad range, indeed, but not broad enough
according to the LRT. Missing taxa include:

  1. All three shrew opossums, which surround Microsyops and Trogosus. Labidolemur correctly nests with Apatemys.
  2. Any metatherians (marsupials), including Caluromys, the proximal outgroup to the Eutheria (placentals) of which Carnivora is the basalmost clade.
  3. Leptictidae are not basalmost placentals, but basal to tenrecs + odontocetes when more taxa are added
  4. Vulpavus and other arboreal, wooly opossum-like Carnivora nest at the base of the Eutheria apart from Erinaceus (hedgehog) and Sorex (shrew) both members of Glires. Missing basal shrew: Uropsilus.
  5. Tupaia is basal to Glires in the LRT. Missing relatives include Macroscelides, Chrysochloris and Necrolestes.
  6. All the rodents and multituberculates are missing. They attract carpolestids and plesiadiformes away from Primates in the LRT.
  7. Altanius requires study, but is represented by teeth and jaw fragments described as plesiadapiform-like.
Figure 2. Apatemys nests as a proximal sister to bats in the Halliday et al. tree. But it shares very few traits with bats. Note the very odd dentition.

Figure 2. Apatemys nests as a proximal sister to bats in the Halliday et al. tree. But it shares very few traits with bats. Note the very odd dentition, largely matched to Labidolemur.

John Wible, is curator of mammals
at the Carnegie Museum of Natural History. After reviewing the Silcox et al. 2010b study, he reported, “It is now clear that any assessment of the origins of primates in the future will have to include apatemyids. Apatemyids are not some freakish dead-end, but significant members of our own history.”

Figure 1. Subset of the LRT focusing on Glires and subclades within.

Figure 3. Subset of the LRT focusing on Glires and subclades within. Slightly out of date, Ptilocercus now nests basal to colugos, but the nesting of Apatemys has not changed.

The LRT invalidates Wible’s statement.
Instead, apatemyids are indeed ‘some freakish-dead taxa’, nesting in Glires, far from Primates. The myth of a plesiadapid-primate interrelationship (that includes the aye-aye, Daubentonia) is not supported when more taxa are added. In the LRT plesiadapiformes, like Daubentonia, are primate-mimics nesting within Glires close to multituberculates and carpolestids. Simply adding taxa recovers this topology. That’s all it takes.


References
Matthew WD and Granger W 1921. New genera of Paleocene mammals. American Museum Novitates 13:1-7
Silcox MT, Bloch JI, Boyer DM and Houde P 2010. Cranial anatomy of Paleocene and Eocene Labidolemur kayi (Mammalia: Apatotheria), and the relationships of the Apatemyidae to other mammals. Zoological Journal of the Linnean Society160: 773–825.

https://www.floridamuseum.ufl.edu/science/labidolemur-kayi-bizarre-extinct-mammal/https://www.eurekalert.org/pub_releases/2010-10/w-uof101110.php

Was the first dinosaur egg soft?

Norell et al. (8 co-authors) 2020
used phylogenetic bracketing to determine that the first dinosaur egg (still unknown) was soft. They made one mistake that invalidates their phylogenetic bracket (Fig. 1).

Figure 1. From Norell et al. 2020 misleading readers by placing pterosaurs, Lagerpeton and Silesaurus in the lineage of dinosaurs after crocodylomorphs.

Figure 1. From Norell et al. 2020 misleading readers by placing pterosaurs, Lagerpeton and Silesaurus in the lineage of dinosaurs after crocodylomorphs.

From the Norell et al. abstract:
“However, pterosaurs—the sister group to dinosauromorphs—laid soft eggs.”

Simply adding taxa reveals this is wrong.
In the large reptile tree (LRT, 1698+ taxa) pterosaurs nest within Lepidosauria. The pterosaur – dinosaur myth was invalidated by Peters 2000, 2007. So we have to toss out pterosaurs as an invalid nesting. What are we left with?

According to Norell et al.
Crocodylia create rigid calcite eggs. So do members of the Theropoda (including birds). So do members of the phytodinosaur clades, Ornithopoda and Macronaria. Exceptions occur among the highly derived Ceratopsia, which lay soft eggs. Two more exceptions include the primitive sauropodomorphs, Massospondylus and Mussaurus. More importantly, egg shellls remain unknown for basal poposaurs, basal crocodylomorphs, basal theropods and basal phytodinosaurs.

When we use phylogenetic bracketing to make a statement like this
we need to be sure that we have the proper phylogeny. Norell et al. relied on tradition and myth rather than testing. They were wrong. In their claodgram, Norell et al. are hopeful that pterosaurs arose between crocodylomorphs and Lagerpeton (a bipedal proterochampsid also not related to dinosaurs). The Norell et al. cladogram was invalidated by Peters 2000 using four prior phylogenetic analyses. Those citations do not appear in Norell et al. (fufilling Bennett’s curse). In the LRT Silesaurus is a poposaur and thus a dinosaur-mimic, less related to dinosaurs than crocodylomorphs.

When we find eggs for Herrerasaurus and Eoraptor
then we can send a manuscript to Nature. Norell et al. were premature at best, misleading and myth perpetuating at worst. That the referees considered this manuscript okay to publish shows the dinosaur – pterosaur myth is still widespread and deeply entrenched, as discussed earlier here.


References
Norell et al. 2020. The first dinosaur egg was soft. Nature https://doi.org/10.1038/s41586-020-2412-8
Peters D 2000b. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.

https://www.cnn.com/2020/06/17/world/soft-dinosaur-eggs-scn/index.html
https://www.cnet.com/news/soft-shelled-dinosaur-eggs-crack-the-mystery-of-missing-fossils/

Oculudentavis reply: bird? lizard? or option #3?

O’Connor et al. 2020 are not giving up without a fight. 
Now they are arguing against a published objection (Li et al. 2020) to their interpretation of Oculudentavis as a strange tiny bird encased in Early Cretaceous Burmese amber. Citation and excerpts are below. You have to admire their courtesy while defending their hypothesis with every weapon they have… except the correct one.

From the O’Connor et al. abstract:
“We welcome any new interpretation or alternative hypothesis regarding the taxonomic affinity of the enigmatic Oculudentavis khaungraae. However, here we demonstrate that Li et al. have failed to provide conclusive evidence for the reidentification of HPG-15-3 as a squamate. We analyse this specimen in a matrix that includes a broad sample of diapsid reptiles and resolve support for this identification only when no avian taxa are included. Regardless of whether this peculiar skull belongs to a tiny bird or to a bizarre new group of lizards, the holotype of Oculudentavis khaungraae is a very interesting and unusual specimen, the discovery of which represents an important contribution to palaeontology.”

‘Regardless’ indeed, as a scientist it’s your job to figure this out. This time it’s not either this or that… it’s something else, a third alternative nobody wants to talk about.

FIgure 1. CT scan model from Li et al. 2020, who denied the presence of a quadratojugal and an antorbital fenestra, both of which are present. Colors applied here.

FIgure 1. CT scan model from Li et al. 2020, who denied the presence of a quadratojugal and an antorbital fenestra, both of which are present. Arrow points to antorbital fenestra Colors applied here. In the LRT Oculudentavis nests with Cosesaurus, a pterosaur precursor. See figure 2.

Interesting that O’Connor et al. bring up taxon exclusion,
yet keep excluding the taxa that would resolve this stand-off, members of the Fenestrasauria (Peters 2000). The O’Connor et al. taxon list was ‘broad’, but not broad enough.

Figure 1. Cosesaurus flapping - fast. There should be a difference in the two speeds. If not, apologies. Also, there should be some bounce in the tail and neck, but that would involve more effort and physics.

Figure 2. Cosesaurus flapping animation. This sister to Oculudentavis in the LRT was a flapping lizard and a pterosaur precursor provided with locked down coracoids, a aternum, strap-like scapulae, an antorbital fenestra a large orbit and bulbous cranium.

From the O’Connor et al 2020 introduction.
“We welcome any new interpretation or alternative hypothesis regarding the taxonomic affinity of the enigmatic Oculudentavis khaungraae.”

No they don’t! They were sent an alternative hypothesis the day after publication. (Not whining. Just stating fact in the face of all their righteous signaling).

“Several of the squamate morphologies described by Li et al. were noted by ourselves in the original manuscript (e.g., pleurodont dentition, morphology of the eye)1. However, we will argue that other features which Li et al. describe as unusual for archosaurs are not incompatible with our original interpretation.”

The solution continues to be the third choice, which both sides continue to overlook (= taxon exclusion).

From the O’Connor et al. text,
“Li et al. criticize our phylogenetic analysis yet provide none themselves.”

Good point! A phylogenetic solution is paramount. Otherwise you’re “Pulling a Larry Martin” trying to make your argument with possibly convergent traits, not last common ancestry, which, when done right, is irrefutable.

The O’Connor et al. text continues,
“However, this does highlight a weakness of a majority of phylogenetic analyses utilized to describe new taxa. If a new specimen is identified as a bird it is analysed in a matrix targeted at birds; if the specimen is identified as a lizard, it is analysed in a matrix targeted at lizards. Descriptions of new taxa rarely include phylogenetic datasets targeted at higher level relationships such as all of Reptilia or Amniota that would be capable of testing alternative placements.”

Another excellent point! That’s why the large reptile tree (LRT, 1697+ taxa) is online and available for anyone to use, precisely for problem taxa, like Oculudentavis.

O’Connor et al. report,
“However, removal of all avian taxa results in Oculudentavis being resolved among squamates.”

That’s interesting! (and supports Peters 2007). By the way, such a phylogenetic leap rarely happens in the LRT. Removing large proximal clades usually results in the next closest clade nesting the enigma taxon.

O’Connor et al. conclude:
“Oculudentavis may represent an outstanding case of convergent evolution between squamates and birds, the likes of which biologists have rarely seen before.”

Well, yes, if you’re referring to flapping, flying lizards (aka ‘pterosaurs’; Peters 2007). This citation is rare due to academic suppression.

Unfortunately, O’Connor et al. are still missing the headline of this story: Oculudentavis is a late-surviving member of the Middle Triassic radiation that produced pterosaurs. The arose from an overlooked third clade of Lepidosaurs, some on which became protorosaur mimics. Others became archosaur mimics.

“However, regardless of whether this peculiar skull belongs to a tiny bird or to a bizarre new group of lizards, the holotype of Oculudentavis khaungraae is a very interesting and unusual specimen, the discovery of which represents an important contribution to palaeontology.”

It won’t be ‘bizarre’ once you understand what Oculudentavis is: a sister to the lepidosaur tritosaur fenestrasaur Cosesaurus. Just expand that taxon list and come to an agreement.

Again, when someone uses the word “bizarre” they have not included all the pertinent taxa. It’s sign they are giving up. Nothing is bizarre in the LRT. All enigmas are nested. No taxon stands alone.

This is what citation avoidance and suppression results in. Neither party understands what they have here. We looked at this exact problem yesterday.

We looked at the Oculudentavis controversy
earlier here, here, here, here and here. And the story has yet to reach a conclusion.

Figure 3. The origin of pterosaurs now includes Kyrgyzsaurus, nesting between Cosesaurus and Sharovipteryx.

Figure 3. The origin of pterosaurs now includes Kyrgyzsaurus, nesting between Cosesaurus and Sharovipteryx.

Postscript:
The post-crania of Oculudentavis remains unknown. It could resemble anything from Cosesaurus (Fig. 3) through pterosaurs, given its Early Cretaceous age and the variety we already find in the clade Fenestrasauria, from which it arose.


References
Li Z, Wang W, Hu H, Wang M, Y H and Lu J 2020. Is Oculudentavis a bird or even archosaur? bioRxiv (preprint) doi: https://doi.org/10.1101/2020.03.16.993949 (Not cited in O’Connor et al. 2020)
O’Connor J Xing, Chiappe L, Schmitz L, McKellar R,  Li G and Yi Q 2020. Reply to Li et al. “Is Oculudentavis a bird or even archosaur?” bioRxiv 2020.06.12.147041 (preprint)
Peters D 2000. A Redescription of Four Prolacertiform Genera and Implications for Pterosaur Phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106 (3): 293–336.
Peters D 2007. The origin and radiation of the Pterosauria. In D. Hone ed. Flugsaurier. The Wellnhofer pterosaur meeting, 2007, Munich, Germany. p. 27.
Xing L, O’Connor JK,; Schmitz L, Chiappe LM, McKellar RC, Yi Q and Li G 2020. Hummingbird-sized dinosaur from the Cretaceous period of Myanmar. Nature. 579 (7798): 245–249.

https://pterosaurheresies.wordpress.com/2020/03/22/oculudentavis-in-more-incredible-detail-thanks-to-li-et-al-2020/

Microsyops enters the LRT between three overlooked shrew opossums

Silcox, Gunnell and Bloch 2020
described the cranium of Microsyops annectens (Leidy 1872, Marsh 1872, Fig. 1), but were not able to nest it phylogenetically due to taxon exclusion. The authors mistakenly kept calling it a plesidapiform and mistakenly considered plesiadapiforms ‘plausible stem primates.’

More taxa
solve this problem.

Figure 1. Micrsyops skull from Silcox et al. 2020. The third tooth is the canine.

Figure 1. Micrsyops skull from Silcox et al. 2020. The third tooth is the canine.

From their abstract:
“While results from phylogenetic analyses support euarchontan affinities, specific relationships of microsyopids to other plesiadapiforms (plausible stem primates), Euprimates (crown primates), Scandentia (treeshrews), and Dermoptera (colugos) are unresolved.”

From the discussion and conclusions:
“The basicranial anatomy of microsyopids does not provide evidence in support of a clear link to any of the extant euarchontans, and suggests that the primitive morphology of this region in Euarchonta was little differentiated from that observed in the primitive placental mammals.”

Figure 1. Not a marsupial, and not a shrew opossum, Palaeothentes nests in the LRT at the base of the Apatemys + Trogosus clade nest to the clade of living shrew opossums within Glires.

Figure 2. Not a marsupial, and not a shrew opossum, Palaeothentes nests in the LRT at the base of the Apatemys + Trogosus clade nest to the clade of living shrew opossums within Glires.

By contrast
in the large reptile tree (LRT, 1698+ taxa) using fewer traits and more taxa, Microsyops nests as a near basal member of Glires (gnawing mammals) between three traditional pouchless ‘marsupials’, the two extant shrew ‘opossums’, Rhyncholestes (Fig. 3) + Caenolestes and Palaeothentes (Miocene. Fig. 2). These nest at the base of Trogosus (Eocene) + the Apatemyidae (Eocene). None of these taxa, other than Apatemys, were included in the Silcox et al. cladograms.

Figure 1. Skull of Rhyncholestes along with in vivo photo.

Figure 3. Skull of Rhyncholestes along with in vivo photo.

Ironcally, ten years earlier,
Silcox, Bloch, Boyer and Houde (2010) wrote: “Microsyopids are the most similar to apatemyids in the basic form of the basicranium of any ‘plesiadapiform’.

Again, adding taxa
(more rodents, rabbits and shrew opossums ) solves this problem. Don’t assume pouchless shrew opossums are marsupials. In the LRT they are gnawing placentals, derived from tree shrews, as we learned earlier here. Call them marsupial-mimics.


References
Leidy J 1872.
Remarks on fossils from Wyoming: Proceedings of the Academy of Natural Sciences, Philadelphia 1872: 19–21.
Marsh OC 1872. Preliminary description of new Tertiary Mammals. Parts I– IV: American Journal of Science 4: 122–128, 202–224.
Silcox MT, Bloch JI, Boyer DM and Houde P 2010. Cranial anatomy of Paleocene and Eocene Labidolemur kayi (Mammalia: Apatotheria), and the relationships of the Apatemyidae to other mammals. Zoological Journal of the Linnean Society160: 773–825.
Silcox MT, Gunnelll GF and Bloch JI 2020. Cranial anatomy of Microsyops annectens (Microsyopidae, Euarchonta, Mammalia) from the middle Eocene of Northwestern Wyoming. Journal of Paleontology, 28pp. 0022-3360/20/1937-2337
doi: 10.1017/jpa.2020.24

wiki/Microsyops

Two papers in one: Haramiyidans and Juramaia

Part 1: King and Beck 2020
bring us their views (again), on ‘early mammal relationships‘. Let’s see how they stack up (again) against the validated (thanks to taxon inclusion) results of the large reptile tree (LRT, 1697+ taxa).

From their abstract:
“Many phylogenetic analyses have placed haramiyidans in a clade with multituberculates within crown Mammalia, thus extending the minimum divergence date for the crown group deep into the Triassic. Here, we apply Bayesian tip-dated phylogenetic methods [definition below] to investigate these issues. Tip dating firmly rejects a monophyletic Allotheria (multituberculates and haramiyidans), which are split into three separate clades, a result not found in any previous analysis. Most notably, the Late Triassic Haramiyavia and Thomasia are separate from the Middle Jurassic euharamiyidans.”

Bayesian tip-dated phylogenetic methods = online definition here.

You heard it here first
Earlier (2016) the LRT rejected a monophyletic Allotheria (separating Haramiavia (Fig. 1) and Thomasia), from Megaconus and all the multituberculates (Fig. 2). Haramiavia and Thomasia nest as pre-mammal synapsids (tritylodontids), not far from Pachygenelus. Several dozen nodes away, Megaconus and the multis nest within the placental clade Glires, at a node more highly derived than tree shrews, rodents and rabbits. So far that hypothesis of relationships has not been tested by other workers, despite several invitations to expand their taxon lists.

Figure 4. Haramiyava dentary showing what a more typical stem mammal dentary and teeth look like. Earlier studies linked this clade to multituberculates, but this dentary was cause to reject that association.

Figure 1. Haramiyava dentary showing what a more typical stem mammal dentary and teeth look like. Earlier studies linked this clade to multituberculates, but this dentary was cause to reject that association.

According to King and Beck 2020,
“Our analysis places Haramiyavia and Thomasia in a clade with tritylodontids, a result that may be the result of insufficient sampling of non-mammaliaform cynodont characters and taxa, and which we consider in need of further testing (see detailed discussion in the electronic supplementary material).” This confirms relationships first recovered by the LRT.

Figure 1. LRT taxa in the lineage of multituberculates arising from Carpolestes and Paulchoffatia.

Figure 2. LRT taxa in the lineage of multituberculates arising from Carpolestes and Paulchoffatia.

The authors continue,
“Our focal dataset was taken from Huttenlocker et al. 2018, which comprises 538 morphological characters scored for 125 mammaliaforms and non-mammaliaform cynodonts.

Unfortunately,
as I mentioned earlier, King and Beck still need to include extant mammals, like montoremes, marsupials, rodents and Daubentonia, rather than rely on fossil taxa exclusively. (See below).

Figure 1. Subset of the LRT focusing on Glires and subclades within.

Figure 3. Subset of the LRT focusing on Glires and subclades within.

Part 2: King and Beck 2020 report:
“A second taxon of interest is the eutherian Juramaia (Fig. 4) from the Middle–Late Jurassic Yanliao Biota, which is morphologically very similar to eutherians from the Early Cretaceous Jehol Biota and implies a very early origin for therian mammals. We also test whether the Middle– Late Jurassic age of Juramaia is ‘expected’ given its known morphology by assigning an age prior without hard bounds. Strikingly, this analysis supports an Early Cretaceous age for Juramaia, but similar analyses on 12 other mammaliaforms from the Yanliao Biota return the correct, Jurassic age.”

Figure 2. Juramaia (Late Jurassic, 160 mya) is more completely known and nests between monotremes and therians (marsupials + placentals).

Figure 4. Juramaia (Late Jurassic, 160 mya) is more completely known and nests between monotremes and therians (marsupials + placentals).

By contrast In the LRT,
Juramaia is a basal protorothere, nesting between Megazostrodon + Sinodelphys and Chaoyangodens, all basal to the extant platypus and echidna in the LRT. Beck and King omit so many key taxa that they do not recover Prototheria, Metatheria and Eutheria.

The same authors publishing on a similar topic in 2019
were reviewed here. The following is one paragraph from that review: King and Beck 2019 bring us a new phylogenetic analysis restricted to Mesozoic mammals. This represents a massive case of taxon exclusion of basal mammals as demonstrated earlier here, because so many basal mammals are still alive! Think of all the tree shrews, arboreal didelphids, and nearly every little creeping taxon in Glires that nest basal to known Mesozoic mammals. You cannot restrict the taxon list to just those extremely rare Mesozoic mammals.

Colleagues: Please use extant mammals in your analyses!
They are guaranteed complete and articulated with soft tissues and gut contents. Figure out your cladogram with as many of these complete specimens as possible. Then… start adding crushed, incomplete and disarticulated fossil taxa. In other words, give yourself a basic education first. Establish a valid tree topology first. Don’t muddle through your studies with questionable traits based on fractured mandibles missing several teeth. As longtime readers know, a valid phylogenetic context is paramount for all further studies.


References
Huttenlocker AK, Grossnickle DM, Kirkland JI, Schultz JA and Luo Z-X 2018. Late-surviving stem mammal links the lowermost Cretaceous of North America and Gondwana. Nature 558, 108–112. 8. (doi:10.1038/s41586-018-0126-y);
King B and Beck R 2019. Bayesian Tip-dated Phylogenetics: Topological Effects, Stratigraphic Fit and the Early Evolution of Mammals. PeerJ
doi: http://dx.doi.org/10.1101/533885.
King B and Beck RMD 2020.
Tip dating supports novel resolutions of controversial relationships among early mammals. Proceedings of the Royal Society B 287: 20200943. http://dx.doi.org/10.1098/rspb.2020.0943

https://pterosaurheresies.wordpress.com/2019/02/07/taxon-exclusion-mars-mesozoic-mammal-study/

New Rhamphorhynchus at the Field: Lauer Foundation Collection

The Lauer Foundation for Paleontology provided
this deep cut Rhamphorhynchus (Fig. 1) to the Field Museum, Chicago, USA. The foundation number is: #LF 1182. Photoshop helps get rid of the surface and deep cuts to see the bones without those distractions.

Figure 1. Another deep cut Solnhofen fossil from the Lauer Collection at the Field Museum, Rhamphorhynchus.

Figure 1. Another deep cut Solnhofen fossil from the Lauer Collection at the Field Museum, Rhamphorhynchus.

Due to its generic look,
the Lauer Foundation specimen enters the large pterosaur tree (LPT, 250 taxa) somewhere in the middle of this genus, distinct from all others, between the ROM specimen (first row, far right, Fig. 2) and the Imhof specimen (second row, far left, Fig. 2).

Figure 2. Rhamphorhynchus specimens to scale. The Lauer Collection specimen would precede the Limhoff specimen on the second row.

Figure 2. Rhamphorhynchus specimens to scale. The Lauer Collection specimen would precede the Limhoff specimen on the second row. Click to enlarge.

This wonderful and complete specimen
nests in the middle of the tested Rhamphorhynchus (Fig. 2) specimens (Fig. 3), outside the clade of the largest specimens (including the large and only juvenile, the Vienna specimen row 2, second from right)..

Figure 4. Subset of the LRT focusing on Rhamphorhynchus.

Figure 3. Subset of the LPT focusing on Rhamphorhynchus.

References
https://www.fieldmuseum.org/blog/meet-pterosaur-flock
https://www.lauerfoundationpse.org/about

New Pterodactylus at the Field: Lauer Foundation Collection

The Lauer Foundation for Paleontology provided
this deep cut Pterodactylus to the Field Museum, Chicago, USA. The foundation number is: #LF 513. It enters the large pterosaur tree (LPT, 250 taxa) distinct from all other tested pterosaurs.

Figure 1. Pterodactylus at the Field Museum from the Lauer Collection

Figure 1. Pterodactylus at the Field Museum from the Lauer Collection

Basically it’s your run-of-the-mill Pterodactylus,
nesting pretty much in the middle of a clade that has divided into several subclades (Fig. 2) each with several members. Now there’s another PhD thesis in the making! Who wants to lump and split?

Figure 2. Subset of the LRT focusing on Pterodactylids and Pterodactylus.

Figure 2. Subset of the LRT focusing on Pterodactylids and Pterodactylus.

It’s worth noting the ribcage,
the one part of any pterosaur that gets the least attention. In many pterosaurs the ribcage forms the torso into a cylinder or a Releaux triangle (triangle with curved sides), but here, as in several anurognathids and Sharovipteryx, the ribcage has a flatter appearance, more elliptical in dorsal view, more like a flying saucer.

Figure 3. Sharovipteryx reconstructed. Note the flattened torso.

Figure 3. Sharovipteryx reconstructed. Note the flattened torso.

References
https://www.fieldmuseum.org/blog/meet-pterosaur-flock

https://www.lauerfoundationpse.org/about

‘Rhamphorhynchus biter’, Aspidorhynchus, enters the LRT

On the subject of the Late Jurassic pterosaur biter, Aspidorhynchus,
Wikipedia reports, “Although it would have looked superficially similar to the present day gar, its closest living relative is actually the bowfin.” 

Figure 1. Aspidorhynchus overall. To the left, off screen, is the pterosaur, Rhamphorhynchus.

Figure 1. Aspidorhynchus overall. To the left, off screen, is the pterosaur, Rhamphorhynchus.

By contrast, 
in the large reptile tree (LRT, 1698+ taxa) Aspidorhynchus (Figs. 1, 2) nests with another swordfish-mimic from the Late Cretaceous Niobrara Sea, Protosphyraena (Fig. 3).

Figure 2. The face of the Wyoming Dinosaur Center CSG 255 specimen of Asphidorhynchus + Rhamphorhynchus with facial bones identified using DGS.

Figure 2. The face of the Wyoming Dinosaur Center CSG 255 specimen of Aspidorhynchus + Rhamphorhynchus with facial bones identified using DGS. The uppermost jugal plate (cyan) may be a postorbital based on phylogenetic bracketing,  but its disconnection from the circumorbital postorbital suggests a jugal replacement in that space.

Among living taxa,
the closest relative is the arowana, Osteoglossum, an Amazon River surface feeder. This may be one clue as to how several Aspidorhynchus specimens met several Rhamphorhynchus specimens, to their mutual doom.

Figure 1. Skull of Protosphyraena. Colors added to march tetrapod homologies and updated here from previous guesstimates. Comapare to figures 3 and 4.

Figure 3. Skull of Protosphyraena. Colors added to march tetrapod homologies and updated here from previous guesstimates. Comapare to figures 3 and 4.

If I’m not mistaken, 
this is a novel hypothesis of interrelationships based on taxon inclusion. If there is an earlier citation, let me know so I can promote it here. Googling the two genera just seems to bring up lists of genera without making a connection between the two.


References
Agassiz L 1843. Recherches sur les poissons fossiles: 5 vols, with atlas (Neuchâtel).
Blainville HMD de 1818. Poissons fossiles. Nouveau Dictionnaire d’Histoire Naturelle 27: 310–395.
Frey E and Tischlinger H 2012. The Late Jurassic pterosaur Rhamphorhynchus, a frequent victim of the ganoid fish Aspidorhynchus?. PLoS ONE. 7 (3): e31945. Bibcode:2012PLoSO…7E1945F. doi:10.1371/journal.pone.0031945.

wiki/Aspidorhynchus