Novel placodont material and paleoenvironment analysis of Triassic deposits of Rocha da Pena (Algarve, southern Portugal)

The Triassic deposits of the Algarve region have been known for almost 200 years with the first vertebrate fossil descriptions published in 1976 by Palain and in 1977 by Russell and Russell. It was followed by the discovery of the monospecific bonebed in Rocha da Pena. The bonebed bears numerous temnospondyl remains, which in 2015 were assigned to a novel species Metoposaurus algarvensis. The occurrence of that taxon suggested a chronostratigraphic range between Carnian and middle Norian. During the following fieldwork, the first Portuguese placodont material was recovered. Based on osteoderm morphology was assigned to genus Henodus, which previously was exclusively known from lower Carnian deposits in Lustnau in southern Germany. Since then new Portuguese fossil material has been recovered including an isolated, nearly complete skull, which is described herein. Based on several features (flat and broad skull with short and broad rostrum composed of maxillae and premaxillae, rectangular shape of the skull, toothless maxillae substituted by longitudinally extending curved groove and non-contacting palatines), the specimen is assigned to the genus Henodus, confirming the occurrence of this taxon in Portugal. This extends its paleogeographic range up till western Laurasia. The occurrence of this taxon in Rocha da Pena may indicate either age of lower Carnian for the local deposits or an extended chronostratigraphic distribution of Henodus. The described specimen comes from a fossiliferous layer that contains isolated remains of placodonts (most probably Henodus), actinopterygian fishes, and the first occurrence of hybodont sharks in the Triassic deposits of Portugal. The gathered sedimentological data-enabled interpretation of the paleoenvironment of the studied sections. The studied deposits can most likely be attributed to a marginal environment, with the transition from playa to near-shore or shallow lagoon.Os depósitos triásicos do Algarve são conhecidos há quase 200 anos com as primeiras descrições de fósseis de vertebrados publicadas em 1976 por Palain e em 1977 por Russell e Russell. Seguiu-se a descoberta de uma cadada de ossos, monoespecífica, na Rocha da Pena, que apresenta inúmeros vestígios de temnospôndilos, que em 2015 foram atribuídos a uma nova espécie Metoposaurus algarvensis. A ocorrência desse táxon sugeriu uma idade entre Carnian e Norian médio. Durante as escavações seguintes, o primeiro material de placodonte português foi recuperado e com base na morfologia da osteoderme foi atribuído ao género Henodus, que anteriormente era conhecido exclusivamente de depósitos carnianos inferiores em Lustnau no sul da Alemanha. Desde então, novo material fóssil foi recuperado, incluindo um crânio quase completo isolado, que é descrito aqui. Com base em várias características (crânio plano e largo com rostro curto e largo composto de maxilares e pré-maxilares, forma retangular do crânio, maxilas desdentadas substituídas por sulco curvo que se prolonga longitudinalmente e palatinos sem contato), o espécime é classificado como género Henodus, confirmando a ocorrência deste táxon em Portugal. Isso estende seu alcance paleogeográfico até o oeste da Laurásia. A ocorrência deste táxon na Rocha da Pena pode indicar uma idade de baixo Carnian para os depósitos locais ou uma distribuição estratigráfica estendida de Henodus. O espécime descrito provém de uma camada fossilífera que contém restos isolados de placodontes (muito provavelmente Henodus), peixes actinopterígios e a primeira ocorrência de tubarões hibodontiformes nos depósitos triásicos de Portugal. Os dados sedimentológicos permitiram a interpretação do paleoambiente das seções estudadas como um ambiente marginal mais provável, com transição de playa para próximo à costa ou ambiente de lagoa rasa

Uszkodzenia przedzwojowe w okołoporodowych porażeniach splotu ramiennego – wyniki leczenia operacyjnego

Background and purpose The authors report their experience in surgical treatment of preganglionic injuries in perinatal brachial plexus palsies. Material and methods Clinical material consisted of 16 children, of both sexes, aged from 2.5 to 33 months (mean 6.2 months), treated surgically between 1994 and 2006. The clinical view of the injury and location of preganglionic lesions was analysed and the description of the performed microsurgical techniques is provided. Control clinical examinations included a group of 14 children. The shortest postoperative observation period was 3 years. The currently accepted scales of evaluation of function of particular joints of the upper limb were used. Results The following outcome was noted after surgical treatment of perinatal brachial plexus palsies with signs of pre- and postganglionic injuries: good shoulder function in 6 cases, and average in 2 others; good elbow function in 4 cases, and average in 7 patients; functional position of the forearm in 9 cases, and good range of pronation and supination in 1 patient; useful function of wrist (flexion/extension) in 4 cases; good motor hand function in 3 cases, and fair in 6 patients. Conclusions In preganglionic perinatal brachial plexus injuries located in the upper-middle part, spinal nerve C7 roots avulsion is the most frequently observed, and in the lower part of the brachial plexus, spinal nerve C8 roots avulsion is the most frequently observed. In preganglionic injuries of the brachial plexus, the number of avulsed spinal nerves has an influence on technical possibilities of performing reconstruction procedures, and then the results of the surgical treatment.Wstęp i cel pracy W pracy przedstawiono własne doświadczenia w leczeniu operacyjnym uszkodzeń przedzwojowych w okołoporodowych porażeniach splotu ramiennego. Materiał i metody Materiał kliniczny stanowiło 16 dzieci, obojga płci, w wieku od 2,5 do 33 miesięcy (średni wiek: 6,2 miesiąca) leczonych operacyjnie w latach 1994–2006. Analizie poddano obraz kliniczny uszkodzenia i lokalizację uszkodzeń przedzwojowych oraz przedstawiono opis zastosowanych technik mikrochirurgicznych. Kontrolne badania kliniczne objęły grupę 14 dzieci. Najkrótszy okres obserwacji pooperacyjnej wynosił 3 lata. Zastosowano powszechnie przyjęte skale oceny funkcji poszczególnych stawów kończyny górnej. Wyniki W wyniku leczenia operacyjnego okołoporodowych obrażeń splotu ramiennego łączących w sobie cechy uszkodzeń przed- i pozazwojowych uzyskano: dobrą funkcję stawu ramiennego w 6, średnią w 2 przypadkach; dobrą funkcję stawu łokciowego w 4, średnią w 7 przypadkach; funkcjonalne ustawienie przedramienia u 9, a dobry zakres ruchu nawracania i odwracania u 1 pacjenta; użyteczną funkcję nadgarstka w zakresie zginania i prostowania w 4 przypadkach; dobrą funkcję ruchową ręki u 3, a zadowalającą u 6 pacjentów. Wnioski W przedzwojowych okołoporodowych uszkodzeniach splotu ramiennego w zakresie części górno-środkowej najczęściej obserwuje się wyrwanie korzeni nerwu rdzeniowego C7, a w zakresie dolnej części splotu ramiennego wyrwanie korzeni nerwu rdzeniowego C8. W uszkodzeniach przedzwojowych splotu ramiennego liczba wyrwanych nerwów rdzeniowych wpływa na techniczne możliwości wykonania zabiegów rekonstrukcyjnych, a co za tym idzie – na wyniki leczenia operacyjnego