A new Ediacaran NeoProterozoic Lagerstatte Sheds Light on Rangeomorphs

The Beothukis/Culmofrons problem and its bearing on Ediacaran macrofossil taxonomy: evidence from an exceptional new fossil locality

Authors:

Liu et al

Abstract:

The late Ediacaran siliciclastic successions of eastern Newfoundland, Canada, are renowned for their fossils of soft-bodied macro-organisms, which may include some of the earliest animals. Despite the potential importance of such fossils for evolutionary understanding, the taxonomic framework within which Ediacaran macrofossils are described is not clearly defined. Rangeomorphs from a newly discovered fossil surface on the Bonavista Peninsula, Newfoundland, require us to reconsider contemporary use of morphological characters to distinguish between genera and species within Ediacaran taxa. The new surface exhibits remarkable preservational fidelity, resolving features smaller than 0.1 mm in dimension in both frondose and non-frondose taxa. Such preservation permits the recognition of rarely observed fourth- and fifth-order rangeomorph branching, offering unparalleled opportunities to investigate the fine-scale construction of rangeomorph taxa including Culmofrons plumosa Laflamme et al., 2012. Our observations enable resolution of taxonomic issues relating to rangeomorphs, specifically overlap between the diagnoses of the frondose genera Beothukis Brasier and Antcliffe, 2009 and Culmofrons. We propose a taxonomic framework for all Ediacaran macrofossils whereby gross architecture, the presence/absence of discrete morphological characters and consideration of growth programme are used to distinguish genera, whereas morphometric or continuous characters define taxa at the species level. On the basis of its morphological characters, Culmofrons plumosa is herein synonymized to a species (Beothukis plumosa comb. nov.) within the genus Beothukis. This discussion emphasizes the need to standardize the taxonomic approach used to describe Ediacaran macrofossil taxa at both the genus and species levels, and raises important considerations for future formulation of higher-level taxonomic groups.

Ward Takes a hit, Romer's Gap not Real: Diverse Tournaisian Mississipian Carboniferous Tetrapods From Nova Scotia Include Several Devonian Taxa

A Diverse Tetrapod Fauna at the Base of 'Romer's Gap'

Authors:

Anderson et al

Abstract:

The lack of fossil tetrapod bearing deposits in the earliest Carboniferous (‘Romer’s Gap’) has provoked some recent discussions regarding the proximal cause, with three explanations being offered: environmental, taphonomic, and collection failure. One of the few, and earliest, windows into this time is the locality of Blue Beach exposed in the Tournaisian deposits at Horton Bluff lying along the Avon River near Hantsport, Nova Scotia, Canada. This locality has long been known but, because the fossils were deposited in high energy settings they are almost always disarticulated, so the fauna has not been described in detail. Recent intensive collection has revealed a diverse assemblage of material, including for the first time associated elements, which permits an evaluation of the faunal constituents at the locality. Although not diagnosable to a fine taxonomic level, sufficient apomorphies are present to identify representatives from numerous clades known from more complete specimens elsewhere. The evidence suggests a diverse fauna was present, including whatcheeriids and embolomeres. A single humerus previously had been attributed to a colosteid, but there is some uncertainty with this identification. Additional elements suggest the presence of taxa otherwise only known from the late Devonian. Depositional biases at the locality favor tetrapod fossils from larger individuals, but indirect evidence from trackways and tantalizing isolated bones evidences the presence of small taxa that remain to be discovered. The fossils from Blue Beach demonstrate that when windows into the fauna of ‘Romer’s Gap’ are found a rich diversity of tetrapods will be shown to be present, contra arguments that suggested this hiatus in the fossil record was due to extrinsic factors such as atmospheric oxygen levels. They also show that the early tetrapod fauna is not easily divisible into Devonian and Carboniferous faunas, suggesting that some tetrapods passed through the end Devonian extinction event unaffected.

Just What WAS the "Parrsboro jaw" From Pennsylvanian Carboniferous Nova Scotia

Redescription and Phylogenetic Analysis of the Mandible of an Enigmatic Pennsylvanian (Late Carboniferous) Tetrapod from Nova Scotia, and the Lability of Meckelian Jaw Ossification

Authors:

Sookias et al

Abstract:

The lower jaw of an unidentified Pennsylvanian (Late Carboniferous) tetrapod from Nova Scotia – the “Parrsboro jaw”- is redescribed in the light of recent tetrapod discoveries and work on evolution of tetrapod mandibular morphology and placed for the first time in a numerical cladistics analysis. All phylogenetic analyses place the jaw in a crownward polytomy of baphetids, temnospondyls, and embolomeres. Several features resemble baphetids and temnospondyls including dermal ornamentation, absence of coronoid teeth, and presence of coronoid shagreen. Dentary dentition is most similar to Baphetes. An adsymphysial toothplate may not preclude temnospondyl affinity. An apparent large exomeckelian fenestra, with the dorsal foraminal margins formed by an unossified element, echoes the morphology of the stem tetrapod Sigournea and is unusually primitive given the other features of the jaw. The jaw may thus provide an example of an intermediate stage in Meckelian element evolution.

Pelycosaur Found in Nova Scotia (either Sphenacodont or Edaphosaurid)

(partially intact rib cage)

A Nova Scotia family out for a walk with their dog has stumbled upon what the province is calling its most significant fossil find.

Patrick Keating and his wife Susie were walking their dog Kitty last month along the Northumberland Shore when something caught their eye.

“(It) looked like a chicken breast, you know, encapsulated in rock. But it was interesting once we found out what it was,” said Susie Keating.

It turned out to be the partial sail, ribcage and backbone of the sail-back reptile, the first to be found in Nova Scotia, the provincial government said in a press release.

"This is a great day for Nova Scotians and the world," Minister of Communities, Culture and Heritage Leonard Preyra said in a statement.

A week later, while walking along the same stretch of beach, the family found the animal’s skull, believed to be 290 million to 305 million years old.

Patrick's brother brought the fossil to the Nova Scotia Museum, which promptly gave it a nickname -- Superstar

“When I finally saw a picture all I could think of was, ‘Oh my God, oh my God,’ because this is part of the missing piece of the puzzle that we're putting together based on the fossils we're finding here in Nova Scotia,” said Ken Adams, Director of Fundy Geological Museum.

Palaeontologists knew the sail-back, a mammal-like reptile, once roamed these parts because in 1994 footprints were found in Nova Scotia's Colchester County, and isolated bones were discovered in 1845 in Prince Edward Island.

Sail-back reptiles have been found in Texas and Europe, which were attached to Nova Scotia more than more than 300 million years ago before the tectonic plates beneath them shifted.

Link (video on the other side of link). 

Is this actually a Dimetrodon?  The video clip shows the museum display with a diagram that highlights the portions found on a dimetrodon skeleton.  So, yes?  No?