Chinese fossil fish discovery


This video is called Evolution fish with fingers. Transitional fossils.

From PLoS ONE:

Fossil Fishes from China Provide First Evidence of Dermal Pelvic Girdles in Osteichthyans

Abstract

Background

The pectoral and pelvic girdles support paired fins and limbs, and have transformed significantly in the diversification of gnathostomes or jawed vertebrates (including osteichthyans, chondrichthyans, acanthodians and placoderms). For instance, changes in the pectoral and pelvic girdles accompanied the transition of fins to limbs as some osteichthyans (a clade that contains the vast majority of vertebrates – bony fishes and tetrapods) ventured from aquatic to terrestrial environments.

The fossil record shows that the pectoral girdles of early osteichthyans (e.g., Lophosteus, Andreolepis, Psarolepis and Guiyu) retained part of the primitive gnathostome pectoral girdle condition with spines and/or other dermal components. However, very little is known about the condition of the pelvic girdle in the earliest osteichthyans. Living osteichthyans, like chondrichthyans (cartilaginous fishes), have exclusively endoskeletal pelvic girdles, while dermal pelvic girdle components (plates and/or spines) have so far been found only in some extinct placoderms and acanthodians. Consequently, whether the pectoral and pelvic girdles are primitively similar in osteichthyans cannot be adequately evaluated, and phylogeny-based inferences regarding the primitive pelvic girdle condition in osteichthyans cannot be tested against available fossil evidence.

Methodology/Principal Findings

Here we report the first discovery of spine-bearing dermal pelvic girdles in early osteichthyans, based on a new articulated specimen of Guiyu oneiros from the Late Ludlow (Silurian) Kuanti Formation, Yunnan, as well as a re-examination of the previously described holotype. We also describe disarticulated pelvic girdles of Psarolepis romeri from the Lochkovian (Early Devonian) Xitun Formation, Yunnan, which resemble the previously reported pectoral girdles in having integrated dermal and endoskeletal components with polybasal fin articulation.

Conclusions/Significance

The new findings reveal hitherto unknown similarity in pectoral and pelvic girdles among early osteichthyans, and provide critical information for studying the evolution of pelvic girdles in osteichthyans and other gnathostomes.

Antarctic warming damages Adélie, chinstrap penguins


This video is called Adelie penguin and chick on Torgersen Island.

From Wildlife Extra:

Antarctic warming changing penguin breeding cycles, and success

Gentoo happier than Adelie & Chinstrap

March 2012. Three penguin species that share the Western Antarctic Peninsula for breeding grounds have been affected in different ways by the higher temperatures brought on by global warming, according to Stony Brook University Ecology and Evolution Assistant Professor Heather Lynch and colleagues.

Lynch and her colleagues used a combination of field work and, increasingly, satellite imagery to track colonies of three penguin species – Adélie, chinstrap and gentoo. The Adélie and chinstrap migrate to the peninsula to breed, while the gentoo are year-round residents.

Rapid warming

The Antarctic is considered one of the world’s most rapidly warming regions. Warmer temperatures move up the breeding cycle, causing the penguins to lay their eggs earlier. The resident gentoo population is able to adapt more quickly and advance their “clutch initiation” by almost twice as much as the other species. Lynch believes this may allow them to better compete for the best nesting space. The Adélie and chinstrap are unaware of the local conditions until they arrive to breed and have not been able to advance their breeding cycles as rapidly.

Gentoo numbers booming, Chinstrap and Adelie declining

In addition, the gentoo prefer areas with less sea ice, and have been able to migrate further south into the Antarctic as the sea ice shrinks. The chinstrap and Adélie species rely more heavily on the abundance of Antarctic krill, which require sea ice for their lifecycle.

The result – the gentoo numbers are increasing while the other two species have noticeably dwindling populations on the Antarctic Peninsula.

The work by Lynch and her team is contained in three papers that have been published online in Polar Biology, Ecology and Marine Ecology Progress Series (MEPS).

See also here. And here.

I had the privilege of seeing all those three penguin species in the Antarctic decades ago. It is heartbreaking that Big Oil and their accomplices ruin the Antarctic this way now.

Global Warming Brings More Lyme Disease, Ticks: here.

Now You Sea It, Now You Don’t: Watch Arctic Sea Ice Melt: here.

Dutch mallard nest webcam


This video from Bakkerswaal nature reserve in the Netherlands is about catching ducks in the traditional way. Those ducks are then ringed, and released, helping to get more information about bird migration etc.

There is a webcam right now of a mallard nest in Bakkerswaal nature reserve in the Netherlands.

Traditional duck catching on Vlieland: here.

Saving young mallards on Vlieland island: here.

Traditional duck catching on Texel: here.