[Biogeography / Evolution • 2016] The Effect of Area and Isolation on Insular Dwarf Proboscideans

Figure 1.  Reconstruction of four insular dwarf proboscideans with their respective mainland ancestors.
Mainland proboscideans: 1, Palaeoloxodon antiquus; 2, Mammuthus columbi; 3, Stegodon zdanskyi.
Insular proboscideans: 4, Palaeoloxodon ‘mnaidriensis’; 5, Palaeoloxodon falconeri; 6, Mammuthus exilis; 7, Stegodon aurorae.

Based on skeletons at Museo di Paleontología, University of Rome, Italy (1), American Museum of Natural History, New York (2), Taylor Made Fossils, U.S. (3), Museo di Paleontología e Geología G.G. Gemmellaro, Palermo, Italy (4), Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt, Germany (5), Santa Barbara Museum of Natural History, Santa Barbara, U.S. (6), Taga Town Museum, Honshu, Japan (7). DOI:   10.1111/jbi.12743 

Abstract

Aim: We investigated the hypothesis that insular body size of fossil elephants is directly related to isolation and surface area of the focal islands.

Location: Palaeo-islands worldwide.

Methods: We assembled data on the geographical characteristics (area and isolation) of islands and body size evolution of palaeo-insular species for 22 insular species of fossil elephants across 17 islands.

Results: Our results support the generality of the island rule in the sense that all but one of the elephants experienced dwarfism on islands. The smallest islands generally harbour the smallest elephants. We found no support for the hypothesis that body size of elephants declines with island isolation. Body size is weakly and positively correlated with island area for proboscideans as a whole, but more strongly correlated for Stegodontidae when considered separately. Average body size decrease is much higher when competitors are present.

Main conclusions

Body size in insular elephants is not significantly correlated with the isolation of an island. Surface area, however, is a significant predictor of body size. The correlation is positive but relatively weak; c. 23% of the variation is explained by surface area. Body size variation seems most strongly influenced by ecological interactions with competitors, possibly followed by time in isolation. Elephants exhibited far more extreme cases of dwarfism than extant insular mammals, which is consistent with the substantially more extended period of deep geological time that the selective pressures could act on these insular populations.

Conclusions

This study provides further support for the applicability of the island rule to the largest terrestrial mammalian herbivorous taxa (see Benton et al., 2010 and Stein et al., 2010 for intriguing indications that very large herbivorous dinosaurs such as titanosaurian sauropods may have also followed the predicted pattern).

The patterns discussed here for body size variation in proboscideans over space and time do not support a significant relationship between isolation and body size decrease for proboscideans. Islands relatively close to the mainland may harbour extremely size-reduced proboscideans as well as normal-sized species. Islands further away than 48 km (the maximum reported distance an Asian elephant can swim) do not harbour the smallest species.

The correlation between area and body size is positive but weak with much scatter around the trend for all proboscideans, but more robust for Stegodon from low latitude islands. Our observations support an ecological hypothesis of body size evolution, inferred from the significant influence of competition on body size evolution (see also Palombo, 2009). On the mainland and on relatively balanced and ecologically rich palaeo-islands such as Sulawesi, interaction with ecologically relevant species resulted in a (relatively) large body size. On islands with more depauperate assemblages, however, release from these ecological interactions appears to have resulted in a smaller body size. In the absence of competitors, body size tends to trend towards a size positively correlated with island area, provided that deep geological time was available to allow the dwarfing process to proceed beyond the initial phases.

Alexandra A. E. van der Geer, Gerrit D. van den Bergh, George A. Lyras, Unggul W. Prasetyo, Rokus Awe Due, Erick Setiyabudi and Hara Drinia. 2016. The Effect of Area and Isolation on Insular Dwarf Proboscideans. Journal of Biogeography. DOI:   10.1111/jbi.12743 

From giant rats to dwarf elephants, island living changes mammals http://gu.com/p/4t5xt

[Ichthyology • 2016] Diversity and Evolution of the Middle American Cichlid Fishes (Teleostei: Cichlidae) with Revised Classification

Fig. 3. Phylogenetic relationships of Middle American heroine cichlids using the 903 terminal taxon population-level sampling analysis based on mitochondrial DNA (mtDNA: cyt b, ND4, COI, 16S) and nuclear DNA (nDNA: S7i1, RAG1, RAG2). The population-level information is based on the cytb marker only, while the skeleton of the tree is based on the multilocus species-level sampling dataset (fig. 2). The first part of the figure shows relationships within herichthyines, the second part within the amphilophines and astatheroines (both highlighted in the inset tree). Other parts of the tree are omitted (see Supplementary material 2). The tree shown is a 50% majority-rule consensus tree obtained with Bayesian inference analysed as five data partitions (see figs. 1‒2 and Methods). Support values (PP) are shown to the right of the nodes. Putative new species are shown in green. Conflicts with existing classification and conflicts between nDNA and mtDNA are shown in red (cf. figs. 1 & 4). Weakly supported nodes are in grey colour. The scale bar represents the average number of substitutions per site. Each species is also shown by a photograph of a specimen in breeding coloration accompanied by a two-letter species-name acronym. See Supplementary material 1 for the specimen sampling of the Middle American species.

Abstract

We present a taxonomically complete and topologically robust molecular phylogeny of the Middle American heroine cichlids based on which we review their diversity and genus-level systematics. In order to ascertain the diversity of the group and its phylogeny we have used three nested taxon sampling analyses of the concatenated nDNA/mtDNA datasets and additionally to these analyses we present a summary of the results of a new Next Generation Sequencing-generated nuclear phylogeny based on a data set of ~ 140,000 informative characters. The NGS ddRAD phylogeny has a species-level sampling covering virtually all species (including the enigmatic Cichlasoma microlepis Dahl, 1960) with multiple sequenced specimens per species. Based on our results the Middle American heroine cichlids are made up of three main clades. The three clades (the herichthyines, the amphilophines, and the astatheroines) are however not each other sister groups since they are interspersed with South American (Australoheros, Caquetaia, Chocoheros, Heroina, Mesoheros) and Antillean (Nandopsis) genera and they represent probably two separate colonization events of Middle America from South America, probably via the Antilles. Our study reveals many cases of cytonuclear discordance and/or introgressive hybridization both at the genus and deeper levels stressing the importance to study the nuclear and mitochondrial phylogenetic signals independently and not solely in concatenated analyses.

We have found that a great majority of morphological characters are ecologically correlated and that they form only a limited number of functionally-determined combinations – i.e. ecomorphs. We have found five main cranial ecomorphs but only two postcranial ecomorphs (the lotic and lentic ecomorphs, plus the undifferentiated ancestral character combination). The cranial and postcranial ecomorphs are not combined completely randomly having produced thirteen modular whole-body ecomorphs. Both the cranial and postcranial ecomorphs, and even their combinations, have evolved repeatedly in the Middle American cichlids in the same habitats both in sympatry as well as in allopatry. Our analyses of the diversity of Middle American cichlid clade support the existence of 31 genera in Middle America (plus six in South America and one in the Greater Antilles) as separate evolutionary lineages occupying separate adaptive zones. Nine new genera are described here for species and species groups that have lacked a genus level name to this day or were associated with other unrelated genera. We also review the species level diversity based on the mtDNA cytb gene population-level analysis. Furthermore, we provide a new biogeographical analysis of the group which explains their evolutionary history and demonstrates that biogeography is a much better indicator of evolutionary relationships in this fish group than are most morphological characters due to their ecological correlation.

Key words: Adaptive radiation, Central America, cytonuclear discordance, introgressive hybridization, freshwater fishes, new genera, putative new species.

New genus and new species:

Chocoheros gen. nov. Říčan & Piálek, 2016

Type species: Cichlasoma microlepis Dahl, 1960

Chortiheros gen. nov. Říčan & Dragová, 2016

Type species: Theraps wesseli Miller, 1996

Cribroheros gen. nov. Říčan & Piálek, 2016

Type species: Heros rostratus Gill in Gill & Bransford, 1877

Darienheros gen. nov. Říčan & Novák, 2016

Type species: Cichlasoma calobrense Meek & Hildebrand, 1913

Isthmoheros gen. nov. Říčan & Novák, 2016

Type species: Cichlasoma tuyrense Meek & Hildebrand, 1913

Kronoheros gen. nov. Říčan & Piálek, 2016

Type species: Cichlasoma umbriferum Meek & Hildebrand, 1913

Mayaheros gen. nov. Říčan & Piálek, 2016

Type species: Heros urophthalmus Günther, 1862

Talamancaheros gen. nov. Říčan & Novák, 2016

Type species: Heros sieboldii Kner, 1863

Wajpamheros gen. nov. Říčan & Piálek, 2016

Type species: Theraps nourissati Allgayer, 1989

Oldřich Říčan, Lubomír Piálek, Klára Dragová and Jindřich Novák. 2016. Diversity and Evolution of the Middle American Cichlid Fishes (Teleostei: Cichlidae) with Revised Classification. Vertebrate Zoology. 66(1): 1-102. 

http://www.senckenberg.de/files/content/forschung/publikationen/vertebratezoology/vz66-1/01_vertebrate_zoology_66-1_rican_1-102.pdf

facebook.com/israquarium/photos/1056982404368358

[Herpetology • 2016] Bothrops sazimai • Another New and Threatened Species of Lancehead Genus Bothrops (Serpentes, Viperidae) from Ilha dos Franceses, Southeastern Brazil

Franceses Island Lancehead | Bothrops sazimai 

Barbo, Gasparini, Almeida, Zaher, Grazziotin, Gusmão, Ferrarini & Sawaya, 2016 DOI: 10.11646/zootaxa.4097.4.4

Abstract

A new insular species of the genus Bothrops is described from Ilha dos Franceses, a small island off the coast of Espírito Santo State, in southeastern Brazil. The new species differs from mainland populations of B. jararaca mainly by its small size, relative longer tail, relative smaller head length, and relative larger eyes. The new species is distinguished from B. alcatraz, B. insularis and B. otavioi by the higher number of ventral and subcaudal scales, relative longer tail and smaller head. The new species is highly abundant on the island, being nocturnal, semiarboreal, and feeding on small lizards and centipeds. Due its unique and restricted area of occurrence, declining quality of habitat, and constant use of the island for tourism, the new species may be considered as critically endangered.

Keywords: Reptilia, Atlantic Forest, Bothrops, Conservation, Island rule, Heterochrony, taxonomy

Diagnosis. Bothrops  sazimai  is  distinguished  from  other  species  of  B.  jararaca  group  by  the  following  combination of characters: (1) larger eyes; (2) shorter and higher head; (3) slender body; (4) relative longer tail; (5) dorsum predominantly grayish and/or brownish; (6) venter creamish white, speckled in gray; (7) postorbital stripes with  the  same  color  of  lateral  saddles;  (8)  usually  two  postoculars;  (9)  22–25  interictals;  (10)  20–24  anterior  dorsals; (11) 20–23 midbody dorsals; (12) 198–214 ventrals in females, 193–206 in males; (13) 54–65 subcaudals in females, 62–70 in males. 

......

Distribution. The new species is known only from the type-locality, Ilha dos Franceses, (Fig. 6). This island has about 15 ha with maximum elevation of 36 m asl covered by secondary Atlantic forest remnants (Ferreira et al. 2007), and located 3.6 Km eastwards from Itaoca beach (Fig. 7). 

Etymology. The specific epithet sazimai represents a patronymic name dedicated to the friend and professor Ivan Sazima, for his invaluable contribution to the study of natural history and conservation of Brazilian fauna, and for his inspiring and pioneering field studies on Bothrops jararaca. Professor Ivan advised and mentored various generations of students and researchers that presently work with diverse systems and organisms, including snakes, amphibians, fishes, mammals, birds, and plants. He published hundreds of scientific contributions, among articles, book chapters, and educational texts. We suggest the standard English name “Franceses Island Lancehead” for the new species. 

FIGURE 4. Active specimens of Bothrops sazimai at night in different macrohabitats on the island.
Over fallen trunks and twigs (A); coiled over trees (B) (MZUSP 22230); two individuals close to one another and moving on the ground (C); on the rocks near the sea (D); coiled on the ground (MZUSP 22232) (E).

Photographs by R. Sawaya (A, E), R. Zorzal (B), F. Barbo (C), and T. Portillo (D).

 Fausto E. Barbo, João Luiz Gasparini, Antonio P. Almeida, Hussam Zaher, Felipe G. Grazziotin, Rodrigo B. Gusmão, José Mário G. Ferrarini and Ricardo J. Sawaya. 2016. Another New and Threatened Species of Lancehead genus Bothrops (Serpentes, Viperidae) from Ilha dos Franceses, Southeastern Brazil.  Zootaxa. 4097(4); 511-529.  DOI: 10.11646/zootaxa.4097.4.4

ResearchGate.net/publication/299602129_Another_new_and_threatened_species_of_lancehead_genus_Bothrops_Serpentes_Viperidae_from_Ilha_dos_Franceses_Southeastern_Brazil

 facebook.com/RicardoJSawaya
Cientistas descobrem nova espécie de jararaca em ilha capixaba http://ciencia.estadao.com.br/blogs/herton-escobar/cientistas-descobrem-nova-especie-de-jararaca-em-ilha-capixaba/ via @estadao

[PaleoOrnithology • 2016] Chiappeavis magnapremaxillo • An Enantiornithine with a Fan-Shaped Tail, and the Evolution of the Rectricial Complex in Early Birds

Chiappeavis magnapremaxillo

 O’Connor, Wang, Zheng, Hu, Zhang & Zhou, 2016
DOI:  10.1016/j.cub.2015.11.036

Highlights

• O’Connor et al. name a new pengornithid enantiornithine honoring Dr. Luis Chiappe

• The new specimen preserves strong evidence that an aerodynamic tail is present

• These new data suggest that Shanweiniao had ornamental feathers

• The unique pengornithid pygostyle may possess simple rectricial bulbs

Summary

The most basal avians Archaeopteryx and Jeholornis have elongate reptilian tails. However, all other birds (Pygostylia) have an abbreviated tail that ends in a fused element called the pygostyle. In extant birds, this is typically associated with a fleshy structure called the rectricial bulb that secures the tail feathers (rectrices). The bulbi rectricium muscle controls the spread of the rectrices during flight. This ability to manipulate tail shape greatly increases flight function. The Jehol avifauna preserves the earliest known pygostylians and a diversity of rectrices. However, no fossil directly elucidates this important skeletal transition. Differences in plumage and pygostyle morphology between clades of Early Cretaceous birds led to the hypothesis that rectricial bulbs co-evolved with the plough-shaped pygostyle of the Ornithuromorpha. A newly discovered pengornithid, Chiappeavis magnapremaxillo gen. et sp. nov., preserves strong evidence that enantiornithines possessed aerodynamic rectricial fans. The consistent co-occurrence of short pygostyle morphology with clear aerodynamic tail fans in the Ornithuromorpha, the Sapeornithiformes, and now the Pengornithidae strongly supports inferences that these features co-evolved with the rectricial bulbs as a “rectricial complex.” Most parsimoniously, rectricial bulbs are plesiomorphic to Pygostylia and were lost in confuciusornithiforms and some enantiornithines, although morphological differences suggest three independent origins.

Keywords: Pengornis, rectrix, tail, Enantiornithes, Pygostylia, Jehol, Cretaceous

Jingmai K. O’Connor, Xiaoli Wang, Xiaoting Zheng, Han Hu, Xiaomei Zhang and Zhonghe Zhou. 2016.  An Enantiornithine with a Fan-Shaped Tail, and the Evolution of the Rectricial Complex in Early Birds. Current Biology.  26(1); 114–119. 

DOI:  10.1016/j.cub.2015.11.036

ResearchGate.net/publication/288889563_An_Enantiornithine_with_a_Fan-Shaped_Tail_and_the_Evolution_of_the_Rectricial_Complex_in_Early_Birds

New enantiornithine bird with an aerodynamic tail found in China

http://english.ivpp.cas.cn/rh/rp/201601/t20160103_158342.html

http://phy.so/371119857 via @physorg_com

[PaleoOrnithology • 2015] Parapengornis eurycaudatus • A New Species of Pengornithidae (Aves: Enantiornithes) from the Lower Cretaceous of China Suggests a Specialized Scansorial Habitat Previously Unknown in Early Birds

Parapengornis eurycaudatus

 Hu, O’Connor & Zhou, 2015.

DOI: 10.1371/journal.pone.0126791 

Abstract

We describe a new enantiornithine bird, Parapengornis eurycaudatus gen. et sp. nov. from the Lower Cretaceous Jiufotang Formation of Liaoning, China. Although morphologically similar to previously described pengornithids Pengornis houi, Pengornis IVPP V18632, and Eopengornis martini, morphological differences indicate it represents a new taxon of the Pengornithidae. Based on new information from this specimen we reassign IVPP V18632 to Parapengornis sp. The well preserved pygostyle of the new specimen elucidates the morphology of this element for the clade, which is unique in pengornithids among Mesozoic birds. Similarities with modern scansores such as woodpeckers may indicate a specialized vertical climbing and clinging behavior that has not previously been inferred for early birds. The new specimen preserves a pair of fully pennaceous rachis-dominated feathers like those in the holotype of Eopengornis martini; together with the unique morphology of the pygostyle, this discovery lends evidence to early hypotheses that rachis-dominated feathers may have had a functional significance. This discovery adds to the diversity of ecological niches occupied by enantiornithines and if correct reveals are remarkable amount of locomotive differentiation among Enantiornithes.

Systematic Paleontology

Aves Linnaeus, 1758 

Ornithothoraces Chiappe, 1995 

Enantiornithes Walker, 1981

Pengornithidae Wang et al., 2014 

Parapengornis eurycaudatus gen. et sp. nov.

urn:lsid:zoobank.org:act:023BF172-3901-4C81-8E78-3BBA9DCCED9B

Holotype: IVPP V18687 (Fig 1), a nearly complete and articulated individual preserved in a single slab, missing only the distal portion of the sternum and some parts of the left hand and right foot, with impressions of the remiges and rectrices.

Locality and Horizon: Lingyuan, Chaoyang, Liaoning, China, Jiufotang Formation, Early Cretaceous.

Etymology: Parapengornis is composed of the Latin prefix ‘para’ and Pengornis indicating the close relationship between the new taxon and Pengornis. The species name eurycaudatus, ‘eury’ means broad and ‘caudatus’ means tail in Latin, indicating the unique broad and laterally expanded pygostyle of the new taxon.

Han Hu, Jingmai K. O’Connor and Zhonghe Zhou. 2015. A New Species of Pengornithidae (Aves: Enantiornithes) from the Lower Cretaceous of China Suggests a Specialized Scansorial Habitat Previously Unknown in Early Birds.  PLoS ONE.  DOI: 10.1371/journal.pone.0126791

[PaleoOrnithology • 2014] Eopengornis martini • Insights into the Evolution of Rachis Dominated Tail Feathers from A New Basal Enantiornithine (Aves: Ornithothoraces)

 Eopengornis martini 

Wang, O'Connor, Zheng, Wang, Hu & Zhou, 2014  

DOI: 10.1111/bij.12370 

We report on a new enantiornithine Eopengornis martini gen. et sp. nov. from the lowest horizon of the Jehol Biota in Hebei, China; dated at 130.7 Mya, this is the second oldest avian bearing fossil deposit in the world, recording the First Appearance Datum of Enantiornithes. The new specimen, only the second enantiornithine and third bird reported from this horizon, preserves numerous synapomorphies with the largest Lower Cretaceous enantiornithine Pengornis houi from the Jiufotang Formation dated at 120 Mya. Together, they form a new avian lineage that lasted over 10 Myr, which is longer than any known clade of Lower Cretaceous enantiornithine. Eopengornis reveals new information about basal enantiornithine morphology such as the presence of a metatarsal V, helping to clarify the early evolution of these dominant Cretaceous avians. Furthermore, Eopengornis preserves a previously unrecognized tail morphology: a pair of elongate fully pennaceous rachis dominated feathers. This discovery confirms hypotheses proposing that the rachis dominated racket-plumes in basal birds represent modified pennaceous feathers. We suggest that the ornamental racket-plumes in enantiornithines and Confuciusornis evolved independently from the basal pygostylian condition, which we infer was a tail formed of normal flight feathers. 

Figure 1. Eopengornis martini gen. et sp. nov. STM24-1.
A, main slab, scale bar = 2 cm. B, close up of the caudal plumage, scale bar = 2 cm. C, close up of the right rectrix, scale bar = 5 mm.

DOI: 10.1111/bij.12370 

Systematic palaeontology

Aves Linnaeus 1758

Ornithothoraces Chiappe 1995

Enantiornithes Walker 1981

Pengornithidae fam. nov

Phylogenetic definition: The most recent common ancestor of Eopengornis martini and P. houi and all its descendants.

Type genus: Pengornis IVPP V15336 Zhou, Clarke & Zhang, 2008.

Included genera: Eopengornis gen. nov. (present study).

Stratigraphic distribution: Huajiying and Jiufotang Formations, 120–130.7 Mya (Zhou, 2006; Jin et al., 2008; Pan et al., 2013).

Geographical distribution: Fengning, northern Hebei Province, and Lingyuan and Dapingfang, Chaoyang, north-eastern Liaoning Province, China.

Diagnosis: Medium to large enantiornithine birds (minor metacarpal projecting distally farther than major metacarpal; straight scapula; dorsolaterally excavated furcula with rami defining a V; metatarsal IV reduced) with the unique combination of the following characters: upper and lower jaws with numerous small teeth (over ten in the maxilla alone); scapular acromion process hooked; sternum with single pair of trabeculae, intermediate trabeculae absent; xiphial region of sternum defines wide V (xiphoid process absent); short pygostyle with rounded distal margin; cranial surface of proximal humerus flat; ulna 15% longer than the humerus; femur almost as long as the tibiotarsus; fibula almost reaching the proximal tarsals; metatarsal I > 30% the length of metatarsal II; first phalanx of hallux longest pedal phalanx; and pedal claws heterogeneous.

Eopengornis martini gen. et sp. nov. 

Holotype: STM24-1, an almost complete and fully articulated subadult individual preserved in a slab (primarily ventral view; see Supporting Information, Fig. S1) and counterslab (primarily dorsal view; Fig. 1), preserving remiges, rectrices, and contour feathers as an outline of the body.

Locality and horizon: Near Luozigou Village, Fengning, Hebei, China. Lower Cretaceous ‘Protopteryx horizon’ (130.7 Mya), the first sedimentary member of the Huajiying Formation (previously also called Dabeigou Formation or Dadianzi Formation) (Jin et al., 2008; Pan et al., 2013).

Etymology: The genus name refers to the older age of the new specimen relative to known specimens of Pengornis; the species name is in honour of the late Larry Martin for his numerous contributions to the field of palaeornithology.

Diagnosis: A pengornithid enantiornithine bird with the following unique characters: numerous, small, occlusally tapered and slightly recurved teeth in the upper and lower jaws; accessory foramina piercing nasal absent; fibula ends in a rounded expansion; and elongate hallux with metatarsal I and the proximal phalanx each almost half the length of metatarsal II.

Xiaoli Wang, Jingmai K. O'Connor, Xiaoting Zheng, Min Wang, Han Hu and Zhonghe Zhou. 2014. 

Insights into the Evolution of Rachis Dominated Tail Feathers from A New Basal Enantiornithine (Aves: Ornithothoraces). Biological Journal of the Linnean Society. [Special Issue: Celebrating Dinosaur Island] 113(3); 805–819. DOI: 10.1111/bij.12370  

  

[PaleoOrnithology • 2008] Pengornis houi • Insight into Diversity, Body Size and Morphological Evolution from the Largest Early Cretaceous Enantiornithine Bird

Pengornis houi

Zhou, Clarke & Zhang, 2008 DOI:  10.1111/j.1469-7580.2008.00880.x

Abstract

Most of Mesozoic bird diversity comprises species that are part of one of two major lineages, namely Ornithurae, including living birds, and Enantiornithes, a major radiation traditionally referred to as ‘opposite birds’. Here we report the largest Early Cretaceous enantiornithine bird from north-east China, which provides evidence that basal members of Enantiornithes share more morphologies with ornithurine birds than previously recognized. Morphological evolution in these two groups has been thought to be largely parallel, with derived members of Enantiornithes convergent on the ‘advanced’ flight capabilities of ornithurine birds. The presence of an array of morphologies previously thought to be derived within ornithurine and enantiornithine birds in a basal enantiornithine species provides evidence of the complex character evolution in these two major lineages. The cranial morphology of the new specimen is among the best preserved for Mesozoic avians. The new species extends the size range known for Early Cretaceous Enantiornithes significantly and provides evidence of forelimb to hind limb proportions distinct from all other known members of the clade. As such, it sheds new light on avian body size evolution and diversity, and allows a re-evaluation of a previously proposed hypothesis of competitive exclusion among Early Cretaceous avian clades.

Keywords: bird evolution; China; Early Cretaceous; Enantiornithes

Aves Linnaeus, 1758 

Enantiornithes Walker, 1981 

Pengornis houi gen. et sp. nov

Holotype: IVPP (Institute of Vertebrate Paleontology and Paleoanthropology, Beijing, China). V15336 comprises a nearly complete skeleton preserved in partial articulation (Figs 1–3) lacking only sternum and pelvic bones and parts of the distalmost left forelimb.

Figure 1. Holotype of Pengornis houi gen. nov., sp. nov. (IVPP V15336). (A) Skeleton. (B) Line drawing.
Anatomical abbreviations: cav, caudal vertebra; cv, cervical vertebra; dr, dorsal rib; dv, dorsal vertebra; fu, furcula; ga, gastralia; hy, hypocleidium; lco, left coracoid; lfe, left femur; lfi, left fibula; lhu, left humerus; lil, left ilium; lpu, left pubis; lra, left radius; lsc, left scapula; lti, left tibiotarsus; ltm, left tarsometatarsus; lul, left ulna; ma, mandible; mcII, major metacarpal; mcIII, minor metacarpal; mtI, metatarsal I; phII-1, first phalanx of the major manual digit; py, pygostyle; rad, radiale; rco, right coracoid; rfe, right femur; rhu, right humerus; rpf, right pubic foot; rra, right radius; rsc, right scapula; rti, right tibiotarsus; rtm, right tarsometatarsus; rul, right ulna; sk, skull; sy, synsacrum; uln, ulnare; un, ungual.

Etymology: ‘Peng’ refers to a Chinese mythological bird, ‘ornis’ is Greek for bird, and ‘houi’ is in honours of Lianhai Hou, a pioneering palaeo-ornithologist.

Locality and horizon: Dapingfang, Chaoyang, Liaoning China; Jiufotang Formation, Early Cretaceous (He et al. 2004).

Diagnosis: Four characters are unambiguously optimized as local autapomorphies of the new species in the phylogenetic analysis: premaxillae unfused throughout their length, hooked scapular acromion, a globose humeral head that projects further proximally than the deltopectoral crest (Characters 1:0, 105:1, 107:1, 108:1; Appendices 1 and 2).

Zhonghe Zhou, Julia Clarke and Fucheng Zhang. 2008. Insight into Diversity, Body Size and Morphological Evolution from the Largest Early Cretaceous Enantiornithine Bird. Journal of Anatomy. 212(5); 565–577. DOI:  10.1111/j.1469-7580.2008.00880.x

HU Han, ZHOU Zhong-He and Jingmai K. O’CONNOR. 2014. A subadult specimen of Pengornis and character evolution in Enantiornithes. VERTEBRATA PALASIATICA. 2014(1); 77-97

http://sourcedb.cas.cn/sourcedb_ivpp_cas/yw/rckyw/200908/W020140121520362403180.pdf

[PaleoOrnithology • 2016] Dingavis longimaxilla • A New Ornithuromorph (Aves) with An Elongate Rostrum from the Jehol Biota, and the Early Evolution of Rostralization in Birds

Dingavis longimaxilla 

 O'Connor, Wang & Hu, 2016  DOI: 10.1080/14772019.2015.1129518

Abstract

A new species of Early Cretaceous ornithuromorph with an elongate rostrum is described from the Sihedang locality of the Lower Cretaceous Yixian Formation in north-eastern China. Like the longipterygid enantiornithines, rostral elongation in Dingavis longimaxilla gen. et sp. nov. is achieved primarily through the maxilla, whereas neornithines elongate the premaxilla and rostralization is far more extreme than observed in early birds. Notably, in the rostrum of Xinghaiornis, the most ‘longirostrine’ Early Cretaceous ornithuromorph, the premaxilla and maxilla contribute to the rostrum equally. These lineages together highlight the diversity of configurations in which early birds experimented with rostralization of the skull. The 65% upper limit in rostral proportions of Early Cretaceous taxa with elongate maxillae and the fact that this morphology was abandoned in more derived taxa suggests that in Aves this skull configuration provided less structural stability.

Keywords: Ornithothoraces, Cretaceous, Jehol, Mesozoic birds, skull

 Jingmai Kathleen O'Connor, Min Wang and Han Hu. 2016. A New Ornithuromorph (Aves) with An Elongate Rostrum from the Jehol Biota, and the Early Evolution of Rostralization in Birds.  JOURNAL OF SYSTEMATIC PALAEONTOLOGY.  DOI:   10.1080/14772019.2015.1129518

Researchgate.net/publication/290170080_A_new_ornithuromorph_Aves_with_an_elongate_rostrum_from_the_Jehol_Biota_and_the_early_evolution_of_rostralization_in_birds

http://zoobank.org/urn:lsid:zoobank.org:pub:9D8A429F-BBA7-47EF-BFD0-ADFB7118833A

[PaleoOrnithology • 2015] Juehuaornis zhangi • Discovery of A New Ornithuromorph Genus, Juehuaornis gen. nov. from Lower Cretaceous of western Liaoning, China

Fig. 1  Juehuaornis zhangi gen. et sp. nov. (holotype, No. SJG 00001)

Abstract

 Here we report on a new basal ornithuromorph bird, Juehuaornis zhangi gen. et sp. nov., based on a nearly complete and articulated subadult skeleton from the Lower Cretaceous Jiufotang Formation in Lingyuan of western Liaoning, China. It displays ornithomorph synapomorphies, such as a synsacrum composed of 12 sacral vertebrae, a short pygostyle, long and curved scapula, U - shaped furcula without a hypocleidum, coracoid with a developed procoracoid process and a concaved lateral margin, a keel extended along the full length of sternum, major and minor metacarpals fused proximally and distally, and proximal phalanx of digit II expanded caudally. The new specimen is distinguishable from other known ornithuromorphs by some unique features including a long rostrum

for approximately 70% the total length of the skull, cranial end of upper jaw hooked, and cranial end of lower jaw straight. The new specimen provides new important morphological information regarding Ornithomorpha, and it represents a new ecotype of this group．

Key words: Ornithuromorpha; Juehuaornis zhangi; Lower Cretaceous; Jiufotang Formation; Lingyuan; western Liaoning

Fig. 1  Juehuaornis zhangi gen. et sp. nov.  ( left: holotype, No. SJG 00001; right: Paratype, No. SJG 00001A)

Ren-fei Wang, Yan Wang and Dong-Yu Hu, 2015. Discovery of A New Ornithuromorph Genus, Juehuaornis gen. nov. from Lower Cretaceous of western Liaoning, China. Global Geology. 2015(1): 7–11

http://sjdz.jlu.edu.cn/fileup/PDF/20150102e.pdf

[PaleoOrnithology • 2013] Xinghaiornis lini (Aves: Ornithothoraces) from the Early Cretaceous of Liaoning: An Example of Evolutionary Mosaic in Early Birds

Xinghaiornis lini 

Wang, Chiappe, Teng & Ji, 2013 DOI: 10.1111/1755-6724.12080

      We describe a new species of Early Cretaceous bird from the Yixian Formation of Liaoning Province. Xinghaiornis lini gen. et sp. nov. is relatively large and characterized by a long, toothless rostrum and an elevated pedal digit I. The design of the skull and feet suggests that this bird was likely a mud-prober. This discovery provides strong support indicating that this avian trophic specialization originated at least 125 million years ago.

Keywords: Early Cretaceous, Xinghaiornis lini, Yixian Formation, avian trophic specialization

Xuri Wang, Luis M. Chiappe, Fangfang Teng and Qiang Ji. 2013. Xinghaiornis lini (Aves: Ornithothoraces) from the Early Cretaceous of Liaoning: An Example of Evolutionary Mosaic in Early Birds. Acta Geologica Sinica (English Edition). 87(3): 686–689.

DOI: 10.1111/1755-6724.12080

Researchgate.net/publication/264351814_Xinghaiornis_lini_Aves_Ornithothoraces_from_the_Early_Cretaceous_of_Liaoning_An_Example_of_Evolutionary_Mosaic_in_Early_Birds

http://www.geojournals.cn/dzxben/ch/reader/view_abstract.aspx?file_no=201303006&flag=1

http://theropoda.blogspot.com/2013/07/xinghaiornis-un-nuovo-enigmatico-aviale.html 

[PaleoOrnithology • 2016] Osteology Supports a Stem-Galliform Affinity for the Giant Extinct Flightless Bird Sylviornis neocaledoniae (Sylviornithidae, Galloanseres)

Fig 15. A skeletal reconstruction for Sylviornis neocaledoniae in a resting pose.
 The missing skeletal parts are estimated (shaded bones), with the pelvis based on proportions of Leipoa ocellata. The bill rhamphotheca is not reconstructed so as to not obscure the underlying skeletal morphology.

DOI: 10.1371/journal.pone.0150871 

Abstract

The giant flightless bird Sylviornis neocaledoniae (Aves: Sylviornithidae) existed on La Grande Terre and Ile des Pins, New Caledonia, until the late Holocene when it went extinct shortly after human arrival on these islands. The species was generally considered to be a megapode (Megapodiidae) until the family Sylviornithidae was erected for it in 2005 to reflect multiple cranial autapomorphies. However, despite thousands of bones having been reported for this unique and enigmatic taxon, the postcranial anatomy has remained largely unknown. We rectify this deficiency and describe the postcranial skeleton of S. neocaledoniae based on ~600 fossils and use data from this and its cranial anatomy to make a comprehensive assessment of its phylogenetic affinities. Sylviornis neocaledoniae is found to be a stem galliform, distant from megapodiids, and the sister taxon to the extinct flightless Megavitiornis altirostris from Fiji, which we transfer to the family Sylviornithidae. These two species form the sister group to extant crown-group galliforms. Several other fossil galloanseres also included in the phylogenetic analysis reveal novel hypotheses of their relationships as follows: Dromornis planei (Dromornithidae) is recovered as a stem galliform rather than a stem anseriform; Presbyornis pervetus (Presbyornithidae) is the sister group to Anseranatidae, not to Anatidae; Vegavis iaai is a crown anseriform but remains unresolved relative to Presbyornis pervetus, Anseranatidae and Anatidae. Sylviornis neocaledoniae was reconstructed herein to be 0.8 m tall in a resting stance and weigh 27–34 kg. The postcranial anatomy of S. neocaledoniae shows no indication of the specialised adaptation to digging seen in megapodiids, with for example, its ungual morphology differing little from that of chicken Gallus gallus. These observations and its phylogenetic placement as stem galliforms makes it improbable that this species employed ectothermic incubation or was a mound-builder. Sylviornis neocaledoniae can therefore be excluded as the constructor of tumuli in New Caledonia.

Summary

Our new anatomical information and phylogenetic analysis finds that the large flightless bird Sylviornis neocaledoniae, originally described as a ratite, but then long regarded as a megapode, to be a stem galliform that forms a clade with Megavitiornis altirostris, forming Sylviornithidae. Neither species are megapodes, but the former perception that they were has led to the suggestion that S. neocaledoniae constructed the large mounds or tumuli in New Caledonia. Ectothermic incubation uniquely characterises Megapodiidae[21], with all included taxa depositing their eggs either in mounds, where heat from composting vegetation warms the eggs, or in holes dug in thermally heated soil or sand where sun can heat it such as in beach dunes. Our finding that it is a stem galliform (and thus not a megapode) makes it most unlikely to have been a mound-builder, as this scenario would require both mound-building and ectothermic incubation to have evolved twice. Furthermore, Sylviornis neocaledoniae shows no specific adaptation for digging to facilitate mound-building, unlike all extant megapodiids, making it even more unlikely that it exhibited ectothermic incubation.

Trevor H. Worthy, Miyess Mitri, Warren D. Handley, Michael S. Y. Lee, Atholl Anderson and Christophe Sand. 2016. Osteology Supports a Stem-Galliform Affinity for the Giant Extinct Flightless Bird Sylviornis neocaledoniae (Sylviornithidae, Galloanseres). PLoS ONE. DOI: 10.1371/journal.pone.0150871

http://biostamps.narod.ru/worldlist/fiji/fiji_2006_ext/fiji_2006_ext.htm

[Herpetology • 2016] From Clinging to Digging: The Postembryonic Skeletal Ontogeny of the Indian Purple Frog, Nasikabatrachus sahyadrensis (Anura: Nasikabatrachidae)

Young metamorphs of the Indian Purple frog Nasikabatrachus sahyadrensis, ready to dig and follow their parents underground. 

DOI: 10.1371/journal.pone.0151114 

Abstract

The Indian Purple frog, Nasikabatrachus sahyadrensis, occupies a basal phylogenetic position among neobatrachian anurans and has a very unusual life history. Tadpoles have a large ventral oral sucker, which they use to cling to rocks in torrents, whereas metamorphs possess adaptations for life underground. The developmental changes that underlie these shifts in habits and habitats, and especially the internal remodeling of the cranial and postcranial skeleton, are unknown. Using a nearly complete metamorphic series from free-living larva to metamorph, we describe the postembryonic skeletal ontogeny of this ancient and unique monotypic lineage. The torrent-dwelling larva possesses a dorsoventrally flattened body and a head with tiny dorsal eyes, robust lower and upper jaw cartilages, well-developed trabecular horns, and a definable gap between the trabecular horns and the tip of the snout. Unlike tadpoles of many other frogs, those of Nasikabatrachus retain larval mouthparts into late metamorphic stages. This unusual feature enables the larvae to maintain their clinging habit until near the end of metamorphosis. The subsequent ontogenetic shift from clinging to digging is correlated with rapid morphological changes and behavioral modifications. Metamorphs are equipped with a shortened tibiafibula and ossified prehallical elements, which likely facilitate initial digging using the hind limbs. Subsequently, the frogs may shift to headfirst burrowing by using the wedge-shaped skull, anteriorly positioned pectoral girdle, well-developed humeral crests and spatula-shaped forelimbs. The transition from an aquatic life in torrents to a terrestrial life underground entails dramatic changes in skeletal morphology and function that represent an extreme in metamorphic remodeling. Our analysis enhances the scope for detailed comparative studies across anurans, a group renowned for the diversity of its life history strategies.

Rapid metamorphic remodeling associated with the development of Indian Purple frog Nasikabatrachus sahyadrensis tadpoles.

DOI: 10.1371/journal.pone.0151114

Gayani Senevirathne, Ashish Thomas, Ryan Kerney, James Hanken, S. D. Biju and Madhava Meegaskumbura. 2016. From Clinging to Digging: The Postembryonic Skeletal Ontogeny of the Indian Purple Frog, Nasikabatrachus sahyadrensis (Anura: Nasikabatrachidae).  PLoS ONE. DOI: 10.1371/journal.pone.0151114

Rapid transformation turns clinging tadpoles into digging adult frogs
  http://phy.so/378559068 via @physorg_com