Daphoenus: basal to only one kind of bear-dog in the LRT

Today’s post
was inspired by a recent PBS Eons YouTube video (link below) on bear-dogs. Earlier we learned that not all bear-dogs are related to one another.

FIgure 1. Skeleton of Daphoneus.

FIgure 1. Skeleton of Daphoenus, basal to Amphicyon major, about the size of a coyote. This mount is digitigrade, but some sources report it was plantigrade, based on fossil footprints.

Daphoenus is correctly mentioned as a basal bear-dog.
It’s important to note, though, that bears are not related to dogs in the large reptile tree (LRT, 1619+ taxa). Cats and hyaenas are closer to dogs and some bear-dogs are more closely related to hyaenas and hyaenodonts (marsupials) in the LRT.

Figure 1. Two skulls attributed to Daphoneus, one with colors added.

Figure 2. Two skulls attributed to Daphoenus, one with colors added. Skull length 20cm.

Daphoenus vetus (Leidy 1853; Middle Eocene to Middle Miocene, 37-16mya). Like related dogs (genus: Canis) this mid-sized predator dug burrows for offspring nesting and hiding sites. Here it nests basal to Amphicyon major, a bear-dog related to dogs.

You can learn more
about bear-dogs here, here and here.


References
Leidy J 1853. Observations on a collection of fossil Mammalia and Chelonia from the Mauvaises Terres of Nebraska. Proc. Acad. Nat. Sci. Philad., 6: 392–394.

wiki/Daphoenus

The bush dog, first known as a fossil, enters the LRT

Figure 1. Speothos is the living bush dog from South America.

Figure 1. Speothos is the living bush dog from South America. This taxon is basal to cats + dogs + hyaenas.

The South American bush dog
Speothos veanticus (Lund 1842; up to 75cm in length; Figs. 1, 2) is traditionally considered a basal dog (family: Canidae). Here Speothos nests at the base of cats + hyaenas + aardwolves + dogs. Miacis is a similar sister basal to sea lions and both are derived from another short-legged carnivore, the European mink, Mustela. Speothos was first identified as a fossil, then as a living taxon. Webbed toes allow this genus to swim more effectively.

Figure 2. Speothos, the South American bush dog, skeleton and in vivo.

Figure 2. Speothos, the South American bush dog, skeleton and in vivo.


References
Lund PW 1842. Fortsatte bernaerkninger over Brasiliens uddöde dirskabning.Lagoa Santa d. 27 de Marts 1840. Kongelige Danske Videnskabernes Selskab Afhandlinger 9:1-16.

wiki/Bush_dog

 

The grrrr…izzly bear enters the LRT

Distinct in skull shape
from the polar bear (Ursus maritimus), the grizzly bear (Ursus arctos) (Fig. 1) had me wondering if perhaps it would nest with dogs like Canis in the large reptile tree (LRT, 1417 taxa). After all there are such things as bear-dogs (genus: Amphicyon). We also looked at the short-face bear (genus: Arctodus) derived from the wolverine (genus: Gulo).

Figure 1. Ursus arctos, the grizzly bear, nests with Ursus maritimus, the polar bear in the LRT, as expected.

Figure 1. Ursus arctos, the grizzly bear, nests with Ursus maritimus, the polar bear in the LRT, as expected.

Alas, U. arctos nested with U. martimus.
Both are bears. Both are derived from mink-weasels like Mustela (extant) and sea weasels like Puijila (Late Oligocene) + Neotherium (Middle Miocene), not dogs.

Ursus arctos (Linneaus 1758 ; up to 3m in length) is the extant grizzly bear. It has a deeper face than U. maritimus, yet nests as a sister taxon here.

Figure 2. Skull of Ursus maritimus, the polar bear. It's worthwhile noting the similarities and differences, which are more distinct than just the colors of their furry coats.

Figure 2. Skull of Ursus maritimus, the polar bear. It’s worthwhile noting the similarities and differences, which are more distinct than just the colors of their furry coats.


References
Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.

Mongoose trifles

Herpestes, the Egyptian mongoose, 
 (Linneaus 1758; extant; 48-60cm in length) has large carnassials. Herpestes is a lower, shorter-legged ancestor to the raccoon, Procyon, with a relatively shorter rostrum and longer, lower body. Surprisingly, the postfrontal and postorbital are elongated here.

Figure 1. The Egyptian mongoose, Herpestes, develops a postorbital bar arising from the layered postfrontal and postorbital reappearing in this clade.

Figure 1. The Egyptian mongoose, Herpestes, develops a postorbital bar arising from the layered postfrontal and postorbital reappearing in this clade. The lacrimal and prefrontal are separated here.

Eupleres from Madagascar 
(Doyère 1835) is the extant Western falnouc, a cat-like mongoose from Madagascar. Note the elongate premaxilla, the gracile mandible, the reduced canine and other rodent-like traits. No postfrontal or postorbital appears here.

Figure 2. Eupleres is a Madagascar mongoose with a long, tree-shrew-like skull with a longer premaxilla.

Figure 2. Eupleres is a Madagascar mongoose with a long, tree-shrew-like skull with a longer premaxilla and smaller, more widely-space, primitive teeth. No postfrontal or postorbital appears here.

Despite the differences in these two taxa,
the large reptile tree nests them in the same clade along with Prohesperocyon, the Late Eocene pre-mole, and Talpa the living mole (a member of Carnivora, not Insectivora).

References
Doyére LMF 1835. Notice sur un mammifére de Madagascar, formant le type d’un nouveau genre de la famille des Carnassiers insectivores de M. Cuvier. Ann. Sci. Nat. Zool. 4: 270–283.
Linnaeus C von 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.

The Miacis-Mustela split within Carnivora

Nesting as the proximal outgroup to all placentals in the LRT
is the slinky, omnivorous, often inverted marsupial didelphid, Caluromys. So that’s the morphology we start with. In the large reptile tree (LRT, 1376 taxa; subset in Fig. 2) Carnivora is the first placental clade to split off. Earlier we looked at the similarity in skulls between Caluromys and didelphid-like basalmost Carnivora, Volitantia, Primates, Glires and Anagale (at the base of the tenrec-odontocete clade).

Always seeking ‘a gradual accumulation of derived traits’,
basal Carnivora, like civets (e.g. Nandinia) in the LRT are likewise slinky, omnivorous and often inverted. That starts to fade away with the raccoons, Procyon and Ailurus and later evolves to hypercarnivory in the extant mongoose (Herpestes). Based on the appearance of the mongoose sister, Cryptoprocta in Madagascar (135 mya) along with the Paleocene appearance of derived Carnivora, like Miacis and Palaeosinopa, basal Carnivora had their genesis early in the Mesozoic.

Gray 1821 defined Viverridae
as consisting of the genera ViverraGenettaHerpestes, and Suricata. All tested taxa are basal members of the Carnivora in the LRT (subset in Fig. 2), so this clade is paraphyletic. Bowdich 1821 defined the clade Carnivora as it is used today.

Most derived Carnivora forsake their veggies
as they become highly specialized for predation. Two clades diverge from a common mongoose-like ancestor: one from a sister to Late Paleocene Miacis (Fig. 1), the other from a sister to Mustela, the European mink. Both are small, long-torsoed and short-legged still resembling the placental outgroup taxon, Caluromys.

Figure 1. Mustela and Miacis (the mink/weasel) compared to scale.

Figure 1. Mustela and Miacis (the mink/weasel) compared to scale.

In the LRT
Miacis is basal to the clade of sea lions, dogs, cats, hyaenas and kin (Fig. 2).

Miacis parvivorus (Cope 1872; Heinrich et al. 2008; 30cm in length; Late Paleocene-Late Eocene) was originally considered a pre-carnivore, but here nests as a derived member of the Carnivora, arising from a Mesozoic sister to Herpestes, the mongoose. It was a sister to Mustela and Hyopsodus in the LRT. Miacis had a full arcade of 11 teeth (x4), but the canines and carnassial were smaller. Miacis had retractable claws, like a cat, and was likely arboreal.

In the LRT
extant Mustela is basal to the clade of wolverines, bears, seals and kin (Fig. 2).

Mustela lutreola (Linneaus 1761; extant European mink; up to 43cm in length) is a fast and agile animal related to weasels and polecats. Mustela lives in a burrow. It swims and dives skilfully. It is able to run along stream beds and stay underwater for one to two minutes. Mustela is basal to PuijilaUrsus and other bears, Phoca and other seals.

Importantly 
note the relatively close affinity of dogs (Canis) and cats (Panthera), in the LRT. That becomes a factor in a genomic study below.

Figure 3. Subset of the LRT focusing on Carnivora, the basalmost eutherian clade. Talpa is the European mole. Shrews and shrew-moles nest within the clade Glires.

Figure 2. Subset of the LRT focusing on Carnivora, the basalmost eutherian clade. The two derived clades arising from Mustela and Miacis are shown here.

How does the clade Carnivora look to traditional paleontologists?
Flynn et al.2005 (Fig. 3) attempted to “assess the impact of increased sampling on resolving enigmatic relationships within the placental clade, Carnivora, by using genomic testing” (so no fossils there). In Flynn et al. the extant Carnivora have their first dichotomy splitting cats from dogs (which are also closely related in the LRT, Fig. 2). No outgroup appears in the Flynn et al. cladogram, which mixes primitive and derived taxa, relative to the LRT. Note, seals + sea lions are monophyletic when fossils are not included. Minks are highly derived here, the opposite of the topology in the LRT. So some relationships are simply inverted, which sometimes happens when the outgroup is not correctly defined.

Figure 4. Carnivora according to Flynn et al. 2005 based on genomic testing.

Figure 3. Carnivora according to Flynn et al. 2005 based on genomic testing. Cryptoprocota is a ‘Malagasy carnivore.”

Once again,
genomic testing does not replicate phenomic testing in deep time. That’s why the LRT is here. So you can test traits vs. genes, always seeking ‘a gradual accumulation of traits’ that echoes or models evolutionary events, without relying on the hope and faith that must come from any analysis that omits fossil taxa. The LRT also provides a list of outgroup taxa back to Devonian tetrapods.

Based on a trait list,
or a photo (Fig. 1), it is easy to see that Miacis and Mustela are closely related. However, in phylogenetic analysis each of these sisters nest at the base of a different derived clade of Carnivora. Cats and dogs remain closely related in the LRT, but both are highly derived relative to the outgroup and basal taxa. The LRT reveals cats are convergent with basal Carnivora, like the cat-like civets.

References
Bowdich TE 1821. An analysis of the natural classifications of Mammalia, for the use of students and travelers. 115 pp.
Cope ED 1872. Third account of new vertebrata from the Bridger Eocene of Wyoming Territory. Proceedings of the American Philosophical Society 12(86): 469-472.
Flynn JJ, Finarelli JA, Zehr S, Hsu J, Nedbal MA 2005. Molecular phylogeny of the Carnivora (Mammalia): Assessing the impact of increased sampling on resolving enigmatic relationships. Systematic Biology. 54 (2): 317–37.
Heinrich RE, Strait SG and Houde P 2008. Earliest Eocene Miacidae (Mammalia: Carnivora) from northwestern Wyoming. Journal of Paleontology. 82 (1): 154–162.
Linneaus C von 1761. Fauna Suecica sistens Animalia Sueciae Regni: Mammalia, Aves, Amphibia, Pisces, Insecta, Vermes. Distributa per Classes, Ordines, Genera, Species, cum Differentiis Specierum, Synonymis Auctorum, Nominibus Incolarum, Locis Natalium, Descriptionibus insectorum. Editio altera, auctior. Stockholmiae: L. Salvii, 48 + 578 pp.,

wiki/Mustela
wiki/Miacis
wiki/Hyopsodus
wiki/Carnivora

Machaeroides and Kerberos enter the LRT

Machaeroides and Kerberos enter the LRT
as related to one another, and both basal to clades within the Carnivora, apart from prior sister candidates. Apparently taxon exclusion was a problem in earlier analyses. Taxon exclusion is minimized in the large reptile tree (LRT, 1364 taxa).

Figure 1. Subset of the LRT focusing on the Mustela clade within the Carnivora with the addition of Kerberos and Machaeroides.

Figure 1. Subset of the LRT focusing on the Mustela clade within the Carnivora with the addition of Kerberos and Machaeroides.

Machaeroides eothen (Matthew 1909; early Eocene, 56mya) has been difficult to nest, with some experts labeling this genus close to Oxyaena, a marsupial creodont. With more taxa sabertooth Machaeroides nests at the base of the StylinodonPsittacotherium clade within the clade Carnivora. Canines are emphasized in this clade. The maxilla contacts the orbit above the lacrimal.

Figure 2. Two Machaeroides skulls in the three views.

Figure 2. Two Machaeroides skulls in the three views.

Kerberos langebadreae (Solé et al. 2015; Middle Eocene, 45 mya) was originally described as sister to the marsupial Hyaenodon. Here Kerberos nests at the base of the Sarkastodon and Patriofelis clade within the larger placental clade, Carnivora. The skull is lower and longer and includes more premolars along with smaller canines.

Figure 3. Kerberos skull in 3 views and colored using DGS methods.

Figure 3. Kerberos skull in 3 views and colored using DGS methods. Perhaps the posterior skull was lower in vivo to match the jaw joint.

References
Matthew WD 1909. The Carnivora and Insectivora of the Bridger Basin, middle Eocene. Memoirs of the American Museum of Natural History 9:289-567.
Solé F, Amson E, Borths M, Vidalenc D, Morlo M, Bastl K 2015. A New Large Hyainailourine from the Bartonian of Europe and Its Bearings on the Evolution and Ecology of Massive Hyaenodonts. (Mammalia). PLoS ONE 10(9): e0135698.
doi:10.1371/journal.pone.0135698

Heretical origin and evolution of moles and shrew-moles

The traditional clade Insectivora
is a now-abandoned clade because its former members have been shown to be polyphyletic. Both shrews and moles are traditional members.

Unfortunately,
a remnant order, Eulipotyphla, still includes both shrews and moles. The large reptile tree (LRT, 1360 taxa, subset Fig. 4) nests moles, like Talpa, within Carnivora, derived from the mongoose, Herpestes, and the traditional canid ancestor, Prohesperocyon. All these taxa (Fig. 1) have transverse premaxillae and long, sharp canines. Talpa and Prohesperocyon both have a bulbous occiput, gracile zygomatic arch and elongate rostrum.

Figure 1. Taxa in the origin and evolution of moles, Herpestes, Prohesperocyon and Talpa.

Figure 1. Taxa in the origin and evolution of moles, Herpestes, Prohesperocyon and Talpa.

Uropsilinae is the clade of shrew-moles
Wikipedia reports, “The shrew moles (Uropsilus) are shrew-like members of the mole family of mammals. They share a full zygomatic arch with all other moles, while this arch is completely absent in shrews.” Notice how this author just ‘pulled a Larry Martin‘? A complete arch is a plesiomorphic (basal) trait. That means it is plesiomorphic for shrews, too. Some shrews, like Rhyncholestes (Fig. 3), retain a complete arch.

Figure 2. The mole-shrew, Uropsilus, is not related to the mole, Talpa (Carnivora), but is related to the shrew (clade Glires).

Figure 2. The shrew-mole, Uropsilus, is not related to the mole, Talpa (Carnivora), but is related to the shrew (clade Glires). Note the long premaxilla, large incisors, tiny canine (orange), arched jugal arch. Image from Hoffmann 1984. Despite the overall similarity of this skull to that of Talpa, note the differences in the dentition and various skull bone proportions, all scored for the LRT.

Uropsilus (Milne-Edwards 1871)
is a shrew-mole (Fig. 2) was described by Hoffmann 1984: “These small insectivores are shrew-like in external appearance, but exhibit a mole0like skull and dentition. The tail is long and forefeet are not enlarged, while the zyogmatic arch is complete, and the tympanic bones form an auditory bulla. Thus, this “shrew-mole” lacks skeletal specializations for digging found in more derived moles, and the derived characters of skull and dentition found in shrews.” Not sure what Hoffman was smoking here, but Uropsilus has a shrew skull (Fig. 2) and readily nests with shrews, like the formerly traditional marsupial, Rhyncholestes, in the LRT, apart from moles.

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

Figure 3. Skull of Rhyncholestes along with in vivo photo. This is the long-nosed shrew-opossum and its skull. This taxon is a sister to Uropsilus, but has a longer snout and more incisors. It does not nest with marsupials in the LRT.

Backstories for today’s players:
Herpestes ichneumon (Linneaus 1758; extant; 48-60cm in length) is the Egyptian mongoose. 9-10 teeth (x4) line the jaws with large carnassials. Derived from a sister to ProtictisHerpestes is a lower, shorter-legged ancestor to Procyon (above) with a relatively shorter rostrum.

Prohesperocyon wilsoni (Wang 1994; Late Eocene, 36 mya) was considered the earliest canid, but here nests between Herpestes, the mongoose, and Talpa the mole. Note the long, pointed skull, expanded occipital and reduced jugal and squamosal. These traits are further emphasized in Talpa (below).

Talpa europaea (Linnaeus 1758, extant) is the extant mole, a small burrowing mammal derived from Herpestes and Prohesperocyon. The large hand, enlarged with a finger-like centralia that extends like a pteroid along the medial axis, is anchored by huge muscles that arise from the anteriorly displaced scapula. The pelvic girdle is fused to an elongate sacrum. The premaxilla is transverse in Talpa and those are large canines.

Uropsilus scoricipes (Milne-Edwards 1871; Hoffmann 1984) is the extant shrew-mole, long considered the link between shrews and moles. Here Uropsilus nests with shrews, apart from moles. Note the tiny canines, deep premaxilla and arched jugal.

Rhyncholestes raphanurus (Osgood, 1924; long-nosed shrew-opossum, Chilean shrew opossum, extant; snout-vent length 20cm), nests in the LRT with another shrew with a complete zygomatic arch, Uropsilus. Wikipedia and other sources consider this shrew-like South American mammal a marsupial, but Wiki also notes that Rhyncholestes lacks a marsupium (pouch). Females have seven nipples. We looked at Rhyncholestes earlier here.

Figure 3. Subset of the LRT focusing on Carnivora, the basalmost eutherian clade. Talpa is the European mole. Shrews and shrew-moles nest within the clade Glires.

Figure 4. Subset of the LRT focusing on Carnivora, the basalmost eutherian clade. Talpa is the European mole. Shrews and shrew-moles nest within the clade Glires in the LRT.

Lots of “low hanging fruit” here…
Someone (= lots of biologists/paleontologists) left these mistakes for others (= yours truly) to repair. Should have been done ages ago. Taxon inclusion is once again the solution to traditional taxon exclusion problems.

References
Hoffmann RS 1984. A review of the shrew-moles (genus Uropsilus) of China and Burma. Journal of the Mammalian Society, Japan 10(2):69–80.
Linnaeus C von 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.
Milne-Edwards  H 1871.
 Descriptions of new species, in footnotes, pp. 92-93 In David, A., Journal d’un voyage en Mongolia et en Chine fait en 1866-68. Nouv. Arch. Mus. d’Hist. Nat. Paris, 7 (Bull.): 75–100.
Osgood WH 1924. Field Mus. Nat. Hist. Publ., Zool. Ser. 14:170.
Wang X 1994. Phylogenetic systematics of the Hesperocyoninae. Bulletin of the American Museum of Natural History. 221: 1–207.

wiki/Uropsilus
wiki/Talpa
wiki/Herpestes
wiki/Prohesperocyon

A fourth tested ‘bear-dog’ also nests with hyaenas

Bone crushing jaws.
That’s what they say about the mighty and ferocious ‘bear-dog’ Amphicyon (Fig. 1). Unfortunately only one species (Amphicyon longiramus) of four tested bear-dogs actually nests with dogs and wolves in the large reptile tree (LRT, 1348 taxa). Two (Amphicyon galushi and A. idoneus) nest with the hyaena (genus: Crocuta). A fourth nests with Thylophoropsa carnivorous marsupial we looked at a few days ago here.

Figure 1. Amphicyon idoneus, from the Yale Museum fossil collection, nests not with dogs, but with hyaenas.

Figure 1. Amphicyon idoneus, from the Yale Museum fossil collection, nests not with dogs, but with hyaenas. The convergence is spectacular, but phylogenetic analysis splits these taxa three ways.

Amphicyon longiramus (Lartet 1836, Blainville 1841; Mid-Miocene to Pliocene, 16–9mya; up to 2.5m) is the wide ranging bone-crushing, bear-dog. This is a wastebasket taxon with some specimens (A. longiramus) related to dogs, others (A. galushi) related to hyaenas, while still others (lower right above) nesting with carnivorous marsupials, traditionally considered creodonts.

?Amphicyon idoneus (YPM VP.013134) was originally considered a bear dog, but here nests with A. galushi a type of hyaena.

From what I can gather
there are several dozen specimens attributed to Amphicyon. It would make a good PhD dissertation to untangle this wastebasket genus.

References
Blainville HM 1841. Osteographie et description iconographique des Mammiferes récentes et fossiles (Carnivores) 1, 2 Paris.
Lartet E 1836. Nomenclature des mammife`res et des coquilles qu’il a trouve´s dans un terrain d’eau douce pre`s de Simorre et de Sansan (Gers). Bulletin de la Socie´te´ Ge´ologique de France 7: 217–220.

wiki/Amphicyon

Sarkastodon: not a giant oxyaenid

Sarkastodon mongoliensis (Granger 1938; AMNH 26641; preserved skull length 37cm; Eocene, 35mya; Fig. 1) was originally considered close to the creodont marsupial, Oxyaena. Here in the large reptile tree (LRT, 1346 taxa, subset Fig. 2) this bear-like carnivore nests in the Carnivora between the wolverine, Gulo, and the seal (Phoca) clade + the Stylinodon clade.

Distinctly the robust nasal of Sarkastodon hangs over the naris, only two robust procumbent premaxillary teeth are present and the multicusp molars have blunt tips, ideal for bone or shell cracking.

Figure 1. Skull of Sarkastodon mongoliensis (Granger 1938) nests not with the creodont marsupial, Oxyaena, but with the wolverine and short-face bear at the base of the seal + Stylinodon clades.

Figure 1. Skull of Sarkastodon mongoliensis (Granger 1938) nests not with the creodont marsupial, Oxyaena, but with the wolverine and short-face bear at the base of the seal + Stylinodon clades.

Sarkastodon is derived from 
wolverines, basal to seals and walruses (Fig. 2).

Figure 1. Subset of the LRT focusing on Basal Mammalia including Creodonta.

Figure 1. Subset of the LRT focusing on Basal Mammalia including Creodonta.

Note
another similar, but smaller traditional oxyaenid, Patriofelis was added to the LRT, nesting between Gulo and Sarkastodon.

Figure 3. Patriofelis skull in two views.

Figure 3. Patriofelis skull in two views. This wolverine-like taxon nests basal to Sarkastodon.

Note the spreading metacarpals and metatarsals
in this taxon (Fig. 4) heading back to the water.

Figure 4. Patriofelis museum mount. This is the sort of wolverine (genus: Gulo) that evolves into seals and walruses.

Figure 4. Patriofelis museum mount. This is the sort of wolverine (genus: Gulo) that evolves into seals and walruses. Sea lions arise elsewhere.

References
Granger W 1938. A giant oxyaenid from the Upper Eocene of Mongolia. American Museum Novitates 969:1–5.
Leidy J 1873. Contributions to the extinct vertebrate fauna of the Western Territories, Rep. US Geol. Surv. Terr. (Hayden), vol. 1, pt. 1, pp. 7-358 (114-116, 316), pis. 1-37.

wiki/Patriofelis
wiki/Sarkastodon

Sinopa: not related to Palaeosinopa

Sinopa rapax (Leidy 1871; Eocene-Early Oligocene; 50mya) was traditionally considered a creodont or sometimes ‘provivverine’ relative of Hyaenodon, but here nests between Dasyurus and Sarcophilus (Fig. 1). It is similar in size to these extant taxa. Not sure about those premaxillary teeth. The dentary canines are larger than the maxillary canines.

BTW,
otter-like Palaeosinopa (Matthew 1901) was first considered a creodont, then a fish-eating pantolestid insectivore (it does get crazy here), but now in the large reptile tree (LRT) nests with eutherian (placental) aquatic seals. like Phoca.

Figure 1. Adding Sinopa to the LRT nests it here, between the extant quoll (Dasyurus) and the extant Tasmanian devil (Sarcophilus).

Figure 1. Adding Sinopa to the LRT nests it here, between the extant quoll (Dasyurus) and the extant Tasmanian devil (Sarcophilus).

The marsupial Sinopa is not related
to Palaeosinopa, the ancestor to seals. Instead Sinopa is one more creodont nesting in the Marsupialia, still… very close to the basalmost clade in the Placentalia (Eutheria), the Carnivora. We’ll discuss creodonts soon.

References
Leidy J 1871. Remains of extinct mammals from Wyoming. Proceedings of the Academy of Natural Sciences Philadelphia1871:113–117.

wiki/Sinopa