[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

New Soviet Enantiornithines



Perhaps you remember when I wrote the following in my post on the birds of Russia and Mongolia (http://www.cmnh.org/fun/dinosaur-archive/2001Feb/msg00618.html)-
"The unnamed coracoids have actually been named by Panteleev (1998), but I have yet to see the paper or hear about it on the list, so I don't know what the names are.  If anyone has the paper, I would be interested to hear from you."
Well, thanks to Tommy Tyrberg I was able to obtain the reference.  Thanks Tommy!  Also, thanks to Jaime Headden for helping me translate it.
The reference in question is-
Panteleev, 1998. New species of enantiornithines (Aves: Enantiornithes) from the Upper Cretaceous of Central Kyzylkum. Russkii Ornitologicheskii Zhurnal. Ekspress-vy.pvsk 35: 3-15.
This is where several new species of enantiornithine are described.  Unfortunately, it's in Russian.  Luckily, with the help of Babelfish and Jaime, I was able to roughly translate it to bring all of you the details.
 
Explorornis Panteleev 1998
Etymology- exploro- to find out; "discover bird"
E. nessovi Panteleev 1998
Holotype- (PO 4819) distally incomplete coracoid (glenoid surface to nearest edge of supracoracoid foramen- 3.5 mm)
Coniacian, Late Cretaceous
Bissekty Formation, Uzbekistan
Diagnosis- A diagnosis for this species is difficult to write, as most differences from other taxa are gradational differences in width, expansion, orientation, etc..  The coracoid process is less prominent than other enantiornithines, but this may be due to wear.
Description- Like Incolornis and Abavornis, this is assigned to the Alexornithidae by Panteleev.  Refer to my post on Russian and Mongolian birds for why I don't agree with Kurochkin's classification scheme.  It is the type species of Explorornis.  This is actually the most complete specimen in the paper, consisting of a coracoid complete except for the distolateral corner.  It has a dorsal fossa, like Protopteryx, enantiornithines and Apsaravis.  It cannot be determined if the lateral edge was convex.  The convex scapular articulation shows it is an enantiornithine.  Other comparable enantiornithines have the following distinguishing characteristics-
Abavornis- distal shaft more expanded medially; midshaft convex laterally?
Alexornis- coracoid process more prominent.
Catenoleimus- larger coracoid process.
Cathayornis? caudatus- shaft expands more gradually; slightly convex distomedial edge.
Concornis- shaft expanded much more distally.
Cruzy coracoid- dorsal fossa more extensive proximally; distal shaft wider; distal area of articular surface projects medially; coracoid process more prominent.
Cuspirostrisornis- shaft expands much less medially.
Enantiornis- articular surface projects laterally; proximal shaft narrower; supracoracoid nerve foramen placed more centrally and proximally.
Eoalulavis- shaft more expanded laterally.
Eoenantiornis- shaft much wider, not expanded medially as much.
Explorornis? walkeri- ventral edge of head slightly convex, not concave; larger, bulbous coracoid process; mid-shaft convex laterally.
Gurilynia- head more angled; coracoid process more prominent; ventral acrocoracoid convexity placed further distally; articular surface wider.
Iberomesornis- distally wider; head narrower.
Incolornis silvae- shaft deeper; shaft less medially expanded; small dorsal bump below articular surface.
Incolornis? martini- distal area of articular surface projects laterally; more prominent coracoid process; small dorsal bump below articular surface.
Largirostrisornis- head oriented proximomedially(?); distomedial(?) edge extremely convex.
Liaoxiornis- head narrower; shaft expands more laterally, less medially.
Longchengornis- shaft wider, expanded more medially; head narrower.
Nanantius? valifanovi- shaft narrower; ventral portion of head angled laterally, projecting laterally from shaft; coracoid process more prominent.
Neuquenornis- shaft narrower, much less expanded medially; laterally convex on midshaft; supracoracoid foramen placed more proximally.
Spanish nestling- shaft much wider.
I lack the references to compare Lingyuanornis, Sinornis and Cathayornis yandica to Explorornis nessovi.
Note that comparisons to most species are difficult, as most European and Chinese specimens are only visible as ventral outlines, while many Mongolian and Russian specimens are incomplete.  Without a phylogenetic framework to provide meaning to the above differences, if any, it is difficult and inadvisable to place Explorornis more specifically within the Enantiornithines.
 
Explorornis? walkeri (Nessov and Panteleev 1993)
= Enantiornis walkeri Nessov and Panteleev 1993
Holotype- (PO 4825) proximal coracoid (glenoid surface to nearest edge of supracoracoid foramen- 6.5 mm)
Coniacian, Late Cretaceous
Bissekty Formation, Uzbekistan
Diagnosis- The ventrally convex coracoid head distinguishes this from most taxa, except possibly Neuquenornis.
Description- This species is based on the proximal half of a coracoid, which makes comparison more difficult than in E. nessovi.  The lateral edge is slightly convex and the articular surface convex, showing it is an enantiornithine.
Alexornis- head concave ventrally; coracoid process narrower.
Catenoleimus- shaft deeper.
Concornis- head projects proximomedially?
Cruzy coracoid- distal area of articular surface projects medially; coracoid process more prominent; head concave ventrally.
Enantiornis- articular surface projects laterally; shaft laterally concave at midlength.
Eoenantiornis- shaft much more expanded laterally.
Explorornis nessovi- ventral edge concave; less prominent coracoid process; mid-shaft not convex laterally.
Gurilynia- head more angled; coracoid process more prominent, pointed; head concave ventrally; articular surface wider.
Iberomesornis- mid-shaft not convex laterally.
Incolornis silvae- proximal shaft deeper; small dorsal bump below articular surface.
Incolornis? martini- distal area of articular surface projects laterally; small dorsal bump below articular surface; head concave ventrally.
Largirostrisornis- head oriented proximomedially(?); head very pointed.
Liaoxiornis- head narrower; mid-shaft not convex laterally.
Longchengornis- head narrower; mid-shaft not convex laterally.
Nanantius? valifanovi- ventral portion of head angled laterally, projecting laterally from shaft; coracoid process more pointed; head concave ventrally.
Neuquenornis- no major differences, but only the mid-section of the shafts can be compared.
Spanish nestling- mid-shaft not convex laterally.
This specimen differs from most taxa because of its ventrally convex head.  Neuquenornis might share this however, and is very close in proportion where they can be compared.  So, I might provisionally assign Explorornis? walkeri to the Avisauridae (Neuquenornis+Avisaurus) and separate it from Explorornis, as I know of no uniquely shared characters between the two species.  The lack of a prominent lateral projection of the head is seen in both Explorornis species, but is also present in a few other enantiornithines (see below).  However, the resemblence of E? walkeri to Neuquenornis is only based on the shape of the mid-coracoid shaft and possible presence of a ventrally convex head in Neuquenornis.  Also, although the translated diagnosis for Explorornis doesn't seem to have any good reasons for placing the two in the same genus, Panteleev might have some that didn't translate well.  So I recommend calling this species Explorornis? walkeri for now.
 
E? sp.
Material- (PO 4818) incomplete coracoid (glenoid surface to nearest edge of supracoracoid foramen- 2.3 mm)
Coniacian, Late Cretaceous
Bissekty Formation, Uzbekistan
Description- This is based on an incomplete coracoid lacking the proximal part of the head and the distomedial corner.  The fact it is only figured in oblique views makes it difficult to compare to the other Explorornis specimens.  However, it does seem to have a wider shaft than both and a more laterodistally expanded shaft than E. nessovi.  The laterally convex shaft and dorsal fossa  suggest it is enantiornithine.  I can't identify any unique characters shared by this an Explorornis, so I don't know if it should be referred to the genus.
E? sp.
Material- (PO 4817) proximal coracoid (glenoid surface to nearest edge of dorsal fossa- ~5.3 mm)
Coniacian, Late Cretaceous
Bissekty Formation, Uzbekistan
Description- This coracoid is not figured, but Panteleev says it resembles E? walkeri more than E. nessovi or the other Explorornis species.  This makes me more hesitant to refer it to Explorornis than the above species.
 
Incolornis Panteleev 1998
Etymology- incola- inhabitant; "inhabitant bird"
Diagnosis- very deep coracoid shaft (>40% of proximodistal head length); proximodorsal coracoid bump.
I. silvae Panteleev 1998
Etymology- silva- forest; "bird inhabiting the forest"
Holotype- (PO 4604) proximal coracoid (glenoid surface to nearest edge of supracoracoid foramen- 2.6 mm)
Coniacian, Late Cretaceous
Bissekty Formation, Uzbekistan
Diagnosis- proximodorsal coracoid bump placed further distally.
Description- This is based on a coracoid lacking the proximal part of the head and the distal fourth or so.  The lateral edge is slightly convex and the articular surface is convex, so this is an enantiornithine.  I can't make out a dorsal fossa, but this could simply be due the photocopy quality.
Abavornis- distal shaft more expanded medially, less expanded laterally.
Alexornis- coracoid process narrower; shaft shallower.
Catenoleimus- shallower shaft; no proximodorsal bump.
Cathayornis? caudatus- shaft expands more medially.
Concornis- shaft more expanded distally.
Cruzy coracoid- distal shaft wider; distal area of articular surface projects medially; coracoid process more prominent; shallower shaft; no proximodorsal bump.
Cuspirostrisornis- shaft concave laterodistally.
Enantiornis- shaft more expanded laterally.
Eoalulavis- shaft more expanded laterally.
Eoenantiornis- shaft much more expanded laterally.
Explorornis nessovi- shaft shallower; shaft more medially expanded; no proximodorsal bump.
Explorornis? walkeri- larger, bulbous coracoid process; mid-shaft convex laterally; shaft shallower; no proximodorsal bump.
Gurilynia- coracoid process more prominent; shaft narrower and shallower; no proximodorsal bump.
Iberomesornis- distally wider.
Incolornis martini- proximodorsal bump placed more proximally.
Largirostrisornis- head oriented proximomedially(?); distomedial(?) edge extremely convex.
Liaoxiornis- head narrower; shaft expands more laterally.
Longchengornis- shaft wider. head narrower.
Nanantius? valifanovi- ventral portion of head angled laterally, projecting laterally from shaft; coracoid process more prominent; shaft shallower; no proximodorsal bump.
Neuquenornis- no proximodorsal bump.
Spanish nestling- shaft much wider.
This coracoid shows a distinctive proximodorsal bump, visible in lateral view, right below the head.  This feature is unknown in other enantiornithines, but seems to be present in I. martini, suggesting they are referrable to the same genus.  Another distinguishing feature of this genus is the extreme dorsoventral depth of the shaft, being over forty percent the length of the head along the articular surface.  Further consideration of this genus' phylogenetic placement will be given below.
I. martini (Nessov and Panteleev 1993)
= Enantiornis martini Nessov and Panteleev 1993
Holotype- (PO 4609) proximal fragment of coracoid
Coniacian, Late Cretaceous
Bissekty Formation, Uzbekistan
Description- This is only known from the very proximal end of a coracoid.  The convex articular surface shows it is enantiornithine, and as noted above, it shares some characters with Incolornis silvae.
Alexornis- coracoid process narrower; shaft shallower.
Catenoleimus- shallower shaft; no proximodorsal bump.
Cruzy coracoid- distal area of articular surface projects medially; coracoid process more prominent; shallower shaft; no proximodorsal bump.
Enantiornis- head medially convex.
Explorornis nessovi- shaft shallower; no proximodorsal bump; head not laterally convex.
Explorornis? walkeri- ventral edge convex; larger, bulbous coracoid process; mid-shaft convex laterally; shaft shallower; no proximodorsal bump; head not laterally convex.
Gurilynia- coracoid process more prominent; shaft shallower; no proximodorsal bump.
Incolornis silvae- proximodorsal bump placed more proximally.
Largirostrisornis- head oriented proximomedially(?).
Nanantius? valifanovi- coracoid process more prominent; shaft shallower; no proximodorsal bump.
Neuquenornis- no proximodorsal bump.
This specimen is very similar to I. silvae, differing only in the slightly more proximally placed proximodorsal bump.  Such a difference is of questionable taxonomic significance and I think there is a strong possibility the two are synonymous, which would make this the senior synonym to I. silvae.  However, such a synonymization shouldn't be done without more study.  As for the phylogenetic placement of Incolornis, the laterally projecting head is known in this genus, Enantiornis, Gurilynia, Nanantius? valifanovi and the Cruzy coracoid.  It is not seen in Explorornis nessovi, Explorornis? walkeri or a Lecho enantiornithine (PVL-4029).  Among more poorly figured species, it seems to be present in Eoenantiornis, Concornis and the Spanish hatchling.  It seems to absent in Iberomesornis, Largirostrisornis and Longchengornis.  The presence of this character in Protopteryx would suggest it is plesiomorphic and does not indicate much about the position of Incolornis.  Therefore, I suggest Incolornis be placed in the Enantiornithines without trying to put it in a more specific clade.
 
Abavornis Panteleev 1998
Etymology- abavus- great-great-grandfather; "great-great-grandfather bird"
A. bonaparti Panteleev 1998
Etymology- after Jose Bonaparte, famous Argentinian paleontologist; "Bonaparte's great-great-grandfather bird"
Holotype- (TsNIGRI 56/11915) coracoid shaft (glenoid surface to nearest edge of supracoracoid foramen- 3.1 mm)
Coniacian, Late Cretaceous
Bissekty Formation, Uzbekistan
Description- This is based on the middle portion of a coracoid, lacking almost all of the head, as well as the distal shaft.  The lateral edge is convex and there is a dorsal fossa, suggesting it is enantiornithine.
Cathayornis? caudatus- shaft expands more laterally, much less medially.
Concornis- shaft much more expanded laterally.
Cruzy coracoid- shaft more expanded laterally.
Cuspirostrisornis- shaft more expanded laterally, less medially.
Enantiornis- shaft more expanded laterally, less medially; supracoracoid nerve foramen placed more centrally and proximally.
Eoalulavis- shaft more expanded laterally.
Eoenantiornis- shaft much wider, expanded more medially, less laterally.
Explorornis nessovi- distal shaft less expanded medially; midshaft not convex laterally.
Iberomesornis- shaft more expanded laterally.
Incolornis silvae- shaft more expanded laterally, less medially.
Liaoxiornis- shaft more expanded laterally.
Longchengornis- shaft more expanded laterally.
Nanantius? valifanovi- shaft more expanded laterally, less medially.
Neuquenornis- shaft more expanded laterally, less medially; supracoracoid foramen placed more proximally.
Spanish nestling- shaft more expanded laterally.
The lack of a head or lateral/medial views makes this specimen difficult to compare to others in way besides it's amount of expansion.  Still, the combination of a highly divergent distomedial edge and a distolateral edge than actually angles inward looks unique.  Where this belongs within the Enantiornithines is currently unknown.
A. sp.
Material- (PO 4605) coracoid shaft
Coniacian, Late Cretaceous
Bissekty Formation, Uzbekistan
Description- This is based off the distal part of a coracoid, missing the distolateral corner.  It closely resembles Avabornis bonaparti, but the lateral edge is straight, not angled inward distally.  Perhaps the edge of A. bonaparti is broken.
 
Catenoleimus Panteleev 1998
Etymology- catena- lineage, leimma- remainder; "remainder of a lineage"
C. anachoretus Panteleev 1998
Etymology- anachoretes- recluse; "reclusive remainder of a lineage"
Holotype- (PO 4606) coracoid shaft (glenoid surface to nearest edge of supracoracoid foramen- 3.2 mm)
Coniacian, Late Cretaceous
Bissekty Formation, Uzbekistan
Description- This is based on perhaps the crappiest holotype of any Mesozoic theropod.  Said to be the middle section of a coracoid shaft, Jaime guessed it was a proximal femur.  Then we mistranslated it to be a proximal metatarsal and easily believed it until we read the description.  I suppose if it had to be a left coracoid shaft in medial view, it isn't deep like Incolornis and has a good-sized rounded coracoid process.  I can't see a fossa in the dorsal view and I seriously doubt such a fragment could be certainly identified as an enantiornithine.  Panteleev places this in Enantiornithines incertae sedis.  I would say Pygostylia incertae sedis, if not indet..  Panteleev says the head is oriented differently than other enantiornithines, but without knowing what edges are broken, I have a hard time agreeing with him.  For now, I'll trust his actual experience with the specimen and recommend keeping it Pygostylia incertae sedis. 
 
Enantiornithines indet.
Material- (PO 4821) proximal coracoid
Coniacian, Late Cretaceous
Bissekty Formation, Uzbekistan
Description-  A distal coracoid, shaft expanded strongly in one direction (medial or lateral).  Possibly best labeled as Pygostylia indet..
 
Anyone who wants the page of figures, just ask offlist.
 
Mickey Mortimer